When to Use Apache Camel?
When to use Apache Camel, a popular JVM/Java environment, and when to use other alternatives.
Apache Camel is one of my favorite open source frameworks in the JVM / Java environment. It enables easy integration of different applications which use several protocols and technologies. This article shows when to use Apache Camel and when to use other alternatives.
Enterprise application integration is necessary in almost every company due to new products and applications. Integrating these applications creates several problems. New paradigms come up every decade, for example client / server communication, Service-oriented Architecture (SOA) or Cloud Computing.
Besides, different interfaces, protocols and technologies emerge. Instead of storing data in files in the past (many years ago), SQL databases are used often today. Sometimes, even NoSQL databases are required in some usecases. Synchronous remote procedure calls or asynchronous messaging is used to communicate via several technologies such as RMI, SOAP Web Services, REST or JMS. A lot of software silos exists. Nevertheless, all applications and products of these decades have to communicate with each other to work together perfectly.
Of course, you could reinvent the wheel for each problem, write some spaghetti code and let the applications work together. Unfortunately, your management will not like the long-term perspective of this solution.
Enterprise Integration Patterns (www.eaipatterns.com) help to fragment problems and use standardized ways to integrate applications. Using these, you always use the same concepts to transform and route messages. Thus, it is a good idea to forget about reinventing the wheel each time you have a problem.
Three alternatives exist for integrating applications. EIPs can be used in each solution.
Implement a individual solution that works for your problem without separating problems into little pieces. This works and is probably the fastest alternative for small use cases. You have to code all by yourself. Maintenance will probably be high if team members change.
Use a framework which helps to integrate applications in a standardized way using several integration patterns. It reduces efforts a lot. Every developer will easily understand what you did (if he knows the used framework).
Use an enterprise service bus to integrate your applications. Under the hood, the ESB also uses an integration framework. But there is much more functionality, such as business process management, a registry or business activity monitoring. You can usually configure routing and such stuff within a graphical user interface – you have to decide at your own if that reduces complexity and efforts. Usually, an ESB is a complex product. The learning curve is much higher. But therefore you get a very powerful tool which should offer all your needs.
Apache Camel is a lightweight integration framework which implements all EIPs. Thus, you can easily integrate different applications using the required patterns. You can use Java, Spring XML, Scala or Groovy. Almost every technology you can imagine is available, for example HTTP, FTP, JMS, EJB, JPA, RMI, JMS, JMX, LDAP, Netty, and many, many more (of course most ESBs also offer support for them). Besides, own custom components can be created very easily.
You can deploy Apache Camel as standalone application, in a web container (e.g. Tomcat or Jetty), in a JEE application Server (e.g. JBoss AS or WebSphere AS), in an OSGi environment or in combination with a Spring container.
Apache Camel is awesome if you want to integrate several applications with different protocols and technologies. Why? There is one feature (besides supporting so many technologies and besides supporting different programming languages) which I really appreciate a lot: Every integration uses the same concepts! No matter which protocol you use. No matter which technology you use. No matter which domain specific language (DSL) you use – it can be Java, Scala, Groovy or Spring XML. You do it the same way. Always! There is a producer, there is a consumer, there are endpoints, there are EIPs, there are custom processors / beans (e.g. for custom transformation) and there are parameters (e.g. for credentials).
If you are a developer, you should be able to recognize what these routes do, don't you?
Two other very important features are the support for error-handling (e.g. using a dead letter queue) and automatic testing. You can test EVERYTHING very easily using a Camel-extension of JUnit! And again, you always use the same concepts, no matter which technology you have to support.
When NOT to Use Apache Camel?
Well, yes, there exist some use cases where I would not use Apache Camel. I have illustrated this in the following graphic (remember the three alternatives I mentioned above: own custom integration, integration framework, enterprise service bus).
If you have to integrate just one or two technologies, e.g. reading a file or sending a JMS message, it is probably much easier and faster to use some well known libraries such as Apache Commons IO or Spring JmsTemplate. But please do always use these helper classes, pure File or JMS integration with try-catch-error is soooo ugly!
Although FuseSource offers commercial support, I would not use Apache Camel for very large integration projects. An ESB is the right tool for this job in most cases. It offers many additional features such as BPM or BAM. Of course, you could also use several single frameworks or products and "create" your own ESB, but this is a waste of time and money (in my opinion).
Several production-ready ESBs are already available. Usually, open source solutions are more lightweight than commercial products such as WebSphere Message Broker (you probably need a day or two just to install the evaluation version of this product)! Well-known open source ESBs are Apache ServiceMix, Mule ESB and WSO2 ESB. By the way: Did you know that some ESB base on the Apache Camel framework (e.g. Apache Service Mix and the Talend ESB). Thus, if you like Apache Camel, you could also use Apache ServiceMix or the commercial Fuse ESB which is based on ServiceMix.
Apache Camel is an awesome framework to integrate applications with different technologies. The best thing is that you always use the same concepts. Besides, support for many many technologies, good error handling and easy automatic testing make it ready for integration projects.
Because the number of applications and technologies in each company will increase further, Apache Camel has a great future. Today we have application silos, in ten years we will probably have cloud silos which are deployed in Goggle App Engine, CloudFoundry, Amazon EC3, or any other cloud service. So I hope that Apache Camel will not oversleep to be ready for the cloud era, too (e.g. by offering components to connect to cloud frameworks easily). But that's future… At the moment you really should try this framework out, if you have to integrate applications in the JVM / Java environment.
By the way: I know that I praise Camel in this article, but I am neither a Camel committer nor working for FuseSource. I just really like this framework.


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Q: How to set the locale on a request using symfony 3.4 I am using symfony 3.4 and I want to set the display locale for a request.
I tried as explained in the Symfony documentation with the following code
namespace AppBundle\EventListener;

use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;

class EventListener
{
    private $tokenStorage;

    public function __construct(TokenStorageInterface $tokenStorage)
    {
        $this->tokenStorage = $tokenStorage;
    }

    public function onKernelRequest(GetResponseEvent $event)
    {
        $request = $event->getRequest();
        $request->setLocale('en');
    }
}

but it doesn't affect the page. On the symfony status bar it still shows me de_DE as locale. I read the explanation on this stackoverflow post, but I feel like I did exactly what is described there. So what did I miss?

A: The custom listener must be called before LocaleListener, which initializes the locale based on the current request. To do so, set your listener priority to a higher value than LocaleListener priority (which you can obtain running the debug:event kernel.request command).
check the documentation https://symfony.com/doc/3.4/translation/locale.html

redpajama_set_name: RedPajamaStackExchange


Belongs to Vinhomes Central Park, this apartment is the ideal place for anyone to live, work, and play. It provides the perfect blend of amenities and necessities to make your decision an easy one including Vincom Center, Vinmec, Vinschool, fitness centers, resort-style pool, children's playground, and much more. Here, your house is featured with a commodious living room, 3 spacious living rooms, and a fully equipped kitchen. The location is close to District 1, 2, 3.


(Boston: New England Historic Genealogical Society), [GreatMig.], I:37.
1Note-book Kept by Thomas Lechford, Esq., Lawyer, in Boston, Massachusetts Bay, from June 27, 1638, to July 29, 1641, Edward Everett Hale, Jr., ed. (Cambridge 1885; rpt. Camden, Maine, 1988). Citations herein refer to the pagination as printed (and not to the manuscript pagination) and will therefore differ from the index entries of the 1885 edition.


Connor Bull (centre) opened the scoring for Steyning Town in their 3-2 extra-time defeat against Bearsted in the third round of the FA Vase. Picture by Derek Martin.
The Barrowmen were edged out in a 3-2 defeat in the third round of the competition away at their Southern Counties East League Premier Division opponents.
It was a dramatic climax with defender Ryan Timms' 90th-minute equalising goal taking the game to extra-time, but it was the home side who stole the win.
Connor Bull had given Gerry Murphy's men the lead before Bearsted hit back and they thought they had won it before Timms struck.
Murphy said: "I was very disappointed to lose.
"I thought we deserved at least a draw but the boys should be extremely proud of the effort we have put in throughout this fantastic cup run.
"The game was end-to-end from our point of view. We were under a lot of pressure from them the first half but from then on we played very well.
"Both teams missed a few chances but getting to extra-time was what we were prepared for as we had already done this in two rounds prior, but to concede late on after a real soft free kick against us was really hard to take.
"But we are a strong group and will bounce back and go again for what has been our main focus to gain promotion."
Town had got through four rounds in this year's competition, beating Kent Football United, Punjab United, Walton & Hersham and Banstead Athletic.
Steyning host Mile Oak back in the league on Saturday.


Виховна: виховувати патріотизм та повагу до культурних скарбів різних народів .
Обладнання: підручник New Opportunity Pre-Intermediate; магнітофонний запис; комп'ютери, презентації та відеоролики підготовані учнями і картка самооцінювання( HO 1).
• підведення підсумків уроку, оцінка діяльності учнів на уроці.
Do you often go to the discotheque?
Is dancing your hobby, your future profession or just occasional entertainment?
Look at the pictures in your students books p.105 and find the dances in the Key Words. What other dances do you know?
1.Now you will listen to three people. Which dance is each person talking about?
And now we shall listen to a radio interview with a dancer of Irish dance group. Your task is to complete sentences in ex.3 p.106 with places and dates.
1. Where is the dance company currently on tour?
2. When is listener seeing the show?
4. Where do they do concerts after London?
5. Where are they going to visit his family?
6. Where do they start next tour?
7. When are they giving next concert?
But nowadays modern ballet is becoming more and more popular thanks to popular TV programs.
Sasha has prepared a presentation ''The Roots of Rap" on the material of your future home task. But before his presentation I want you to match the Key Words ex.2 p.116.
1. Where did Hip Hop begin?
2. Why did middle-class people leave the Bronx?
3. Who were the Black Spades?
4. Why is Jamaica important in the history of rap?
5. Do many people still do break dancing?
6. Why were the group Run-DMC important?
7.Name two things that influenced Hip Hop fashion.
And now your home task: Reread the text on p.116 again, do ex.4-6 to master the topic and be ready to tell about Hip Hop or any other dance style. Have you got any questions as to the home task or unit material? If not, thanks for the lesson. See you soon!
Учитель английского языка Витвицкая Л.А. Херсонского лицея Журналистики, Экономики и Правоведения предлагает план-конспект интегрированного с информатикой и культуроведения урока в 11 классе и презентации - ученических работ к коллективному проекту «Мы любим танцевать!» сделанных учениками 11-Б класса.


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PSLS • News • PS Vita / PlayStation Vita News, Trophies, Reviews, and More • PS3 / PlayStation 3 News, Trophies, Reviews, and More
PlayStation 3 & PS Vita Video Game Releases: March 31st – April 6th, 2013
Jason DunningSunday, March 31, 2013
While not nearly as exciting as last week, which gave us BioShock Infinite, you can expect a new MMO in the form of Defiance, the upgraded version of Ninja Gaiden 3, and a couple of Grand Theft Auto PS2 Classics.
*All titles listed are releasing in North America and Europe, unless otherwise noted.
Defiance (Retail & PSN)
Grand Theft Auto: Liberty City Stories (PSN)
Grand Theft Auto: Vice City Stories (PSN)
Ion Assault HD (PSN)
Ninja Gaiden 3: Razor's Edge (Retail & PSN)
Nun Attack (PSN) – EU
Borderlands 2 'Ultimate Vault Hunter Upgrade'
Capcom Arcade Cabinet: Game Pack 4
Capcom Arcade Cabinet: Side Arms
Capcom Arcade Cabinet: Legendary Wings
Capcom Arcade Cabinet: Trojan
*Keep in mind that all release dates are subject to change and more games will be added to both regions on Tuesday/Wednesday with our PlayStation Store Global Update.
Check out our April 2013 release dates page to find out what else is releasing this month, and feel free to let us know in the comments which game(s) you'll be buying this week.
Tags: Defiance, Ninja Gaiden 3: Razor's Edge

redpajama_set_name: RedPajamaCommonCrawl


by an introduction and a commentary.
of Tertullian, written in his pre-Montanist days.
The Introduction and Notes are not intended to be exhaustive.
thought and practice of an ancient Christian community.
Edited and translated by Canon Ernest Evans, 1953. Transcribed by Roger Pearse, 2002.


i've been thinking about the pattern of high & low moments we all seem to go through in life. it seems they follow each other the way that life & death do. do we figuratively die in some moments so that we can find restored life in another one? the way we go to sleep at night and wake in the morning parallels that idea. when we sleep we appear lifeless, but in the morning we find a fresh look at things and another chance to do things right. i think that's a pretty cool idea.


no you say come on build battle show up 777 times and then light shines on you and 3 years later you have build battle Click here to comment on this answer Guest answered:... On PS4 & Xbox One, if you're using the Combat Pro preset, you can enter Build Mode with B on Xbox, or O on PS4. Wall pieces can then be edited using G on PC, and B again on Xbox or O on PS4. Wall pieces can then be edited using G on PC, and B again on Xbox or O on PS4.
The best place to get cheats, codes, cheat codes, walkthrough, guide, FAQ, unlockables, tricks, and secrets for Battle Islands for PC.


text:
NEWS ( VIRUS EDITION )
As coronavirus vaccine begins to roll out, FDA seeks to reassure the public on safety – Laurie McGinley
Will You Be a Hazardous to Health Covid Vaccine Guinea Pig? – "US-led Western officials, Pharma, and their press agent media are going all-out to con people into believing hazardous covid vaccines are safe. Will you allow them to risk your health and well-being by being part of a high-risk, uncontrolled experiment that could be adversely life-altering for many participants? All vaccines are hazardous to human health. They take years to develop — around 90% failing to be approved." – Stephen Lendman
Unlike UK, U.S. FDA Allows Pregnant and Nursing Women to Receive Experimental Pfizer COVID Vaccine – "Both governments have issued guidelines for the new vaccines, one set of guidelines for doctors and healthcare providers who will administer the vaccine, and a shorter set of guidelines for "recipients" who plan on taking the vaccine. Even though these guidelines cover the same vaccine from the same company (Pfizer), there are notable differences." – Brian Shilhavy
The COVID Vaccine Is Here… And So Are Potential Side Effects… (VIDEO) – "The UK and Russia have begun their mass COVID vaccination campaigns and it won't be long from now until the experimental shot is deployed in your town. Meanwhile Canada, the US and Mexico are among a growing list of countries who have approved the Pfizer vaccine. In this report, we examine some of the possible adverse events the CDC and FDA will be looking for," – Spiro Skouras – SPIRO'S VIDEOS ARE ALWAYS GOOD!!!
When Do We Start Coming out of the Covid-19 Mass Hysteria? – "The Covid-19 hysteria, scientifically called mass psychogenic illness, that began in March has yet to peak. And if some have it their way it will continue indefinitely, merely going, in medical terminology, from epidemic to endemic. That is, it will never fully go away no matter what." – Michael Fumento
Physician Specialists Urge CDC to Consider A Safe & Powerful Treatment For COVID-19 – Madhava Setty, MD – SOME MORE BACKGROUND INFO ON IVERMECTIN!!!
COVID-19 tyrants now set sights on Christmas – "Watch out. One of Joe Biden's coronavirus advisory board members told CNN that Americans need to give up their Christmas parties in order to help contain the spread of COVID-19. Who died and made these political hacks the keeper of the constitutional rights?Maybe the pinheads who point fingers at Americans gathering for Christmas ought to turn their pinhead-y chastisements on the Democrats who keep getting outed for doing just what the pinheads say the rest of us can't. Better yet, maybe these pinheads ought to keep quiet. We know how to wash our hands, Washington. We don't need more tyrants coming for our rights, for our rights to choose, for our rights to self-regulate and run our own lives — for Christmas, in much the same way they came for Thanksgiving, in much the same way they came for Easter. " – Cheryl K. Chumley – GOOD OPINION PIECE FROM CHERYL!!!!!!!!!!!!!!!!!!!!!!!
Willing Slaves of the Covidian State? – "Ultimately, it comes down to a simple question: Are enough people actually going to get their heads out the sand, switch off the Brainwasher in the corner of their living rooms, and actually start to think critically about what is happening, such that the "reality creators" are held to account and stopped in their tracks? Or are they simply happy to go on accepting those comfortable lies, rejecting the uncomfortable truths, and so find ourselves slipping further into the Land of Unreality, where the Shadows Reign, and where a powerful clique of despicable technocrats run almost every aspect of our lives from the time we wake to the time we go to sleep?" – Rob Slane – GOOD ARTICLE FROM ROB!!!!!!!!!!!!!!!!
How to Wear a Face Mask and Still Show Dissent Against Tyranny – John C. A. Manley
Conflicts of interest among the UK government's covid-19 advisers – Paul D Thacker – AS THE SAYING GOES, FOLLOW THE MONEY!!!!!!!!!!!!!!!!!!!!!!!!
Cuomo Says New York City Indoor Dining Will Close Monday – Shelly Banjo
Canadian Restaurant Owner Charged With 'Trespassing' After Reopening in Defiance of Lockdown Orders – "How can you 'trespass' on your own property?" – Patrick Carroll
Hunter Biden Subpoenaed Over Burisma, Two Dozen Other Entities As Part Of Four Investigations – Tyler Durden
This is who they are: What media & Big Tech did with Hunter Biden laptop story isn't a bug, but a feature – "The legacy and social media uniting to suppress a scandal involving Joe Biden's son before the US election, and cheering censorship of a newspaper founded by Alexander Hamilton, isn't hypocrisy; it's their raison d'etre. Folks who've been relying on the New York Times, Washington Post, CNN or NPR, may need catching up at this point, so here's the short version:" – Nebojsa Malic
Time for Another Absurd Person of the Year Award – "This justification is ridiculous, for Biden is a 50-year politician, who has become a puppet of the far-left. Neither of these partisan Democrats showed any ability to heal America or bridge the political divide. Biden nor Harris expressed any "empathy" for middle-class Americans who are struggling through this epidemic. In fact, Biden and Harris want to extend the COVID-19 lockdown and make economic conditions even more difficult for average Americans. This choice shows the type of arrogance that exists at Time Magazine. Fortunately, Americans are deserting Time Magazine," – Jeff Crouere
'Office mates': Joe Biden, Hunter Biden, Jim Biden, Jill Biden — and the Red Chinese? – "With an email surfacing of Hunter Biden asking for keys for his dad and a representative of a red Chinese tycoon in a shared office, the ground gets shakier under House Biden as being so very pure." – Monica Showalter
Roaming Charges: Negative Creep – "Under Biden we're set to experience four years (if he lasts that long) of negative creep, a steady recrudescence of the same policies–economic, social, environmental and military–which led us to into the very quagmire where nearly all of us are now inexorably sinking. Predictably, Biden's sterile roster of cabinet picks seem geared toward appeasing a mythical political center that no longer exists, if it ever did." – Jeffrey St. Clair
John Kerry's Think Tank Calls for War With Russia Over Climate Change – "Recently-appointed Special Presidential Envoy for Climate John Kerry has announced his intention of dealing with the pressing issue of global warming as a national security concern. For the ASP, climate change constitutes an "accelerant of instability" and a "threat multiplier" that will "affect the operating environment," and notes that Kerry will have three priorities in his role as President Biden's right-hand man. What were those three priorities? Making sure people in the Global South could eat and have access to safe drinking water? Reparations? Disaster relief or response teams? Cutting back on fossil fuel use? Indeed not. For the ASP, the primary objectives were: A huge rebuilding of the United States' military bases, Countering China in the Pacific, Preparing for a war with Russia in the newly-melted Arctic. " – Alan Macleod
Trump's Last Chance to Snub the Deep State – "I am not the only one hoping that Donald Trump will do the right thing with Julian Assange, and Edward Snowden too. The last president, one Trump hates, first put Assange's key whistleblower in prison, in isolation, under torture. Chelsea Manning was sentenced to 35 years. Obama leaving office with a gesture of "goodwill", commuted Chelsea's sentence once she served seven years. She was later jailed for another year for not snitching on Julian. Tulsi Gabbard, the only Democratic presidential candidate in 2020 who wasn't a war hawk, is asking Trump for goodwill. She tweeted tagging Trump, "Since you're giving pardons to people, please consider pardoning those who, at great personal sacrifice, exposed the deception and criminality of those in the deep state," and named Assange and Snowden for him to drop charges." – Ron Ridenour
The YouTube Ban Is Un-American, Wrong, and Will Backfire – "Silicon Valley couldn't have designed a better way to further radicalize Trump voters" – Matt Taibbi
How the Supreme Court Doomed the US & the West – Martin Armstrong
Imperialism 2.0: Notes From The Edge Of The Narrative Matrix – "The new imperialism doesn't look like old-school ground invasions, it looks like multi-front cold wars, economic warfare, blockades and starvation sanctions, drone strikes, arming proxy militias, CIA-backed coups, sprawling tech surveillance networks, mass psyops of unprecedented sophistication and narrative management systems to facilitate them.We've all spent our lives since childhood watching Hollywood movies and TV shows about evil villains doing wicked deeds to try and rule the world yet hardly anyone ever notices that that's exactly what the US empire is. " – Caitlin Johnstone – MORE GOOD OBSERVATIONS FROM CAITLIN!!!
Chinese Military Bases in The Caribbean? – "China also seems to have a military agenda in the Caribbean region… Chinese Defense Minister Wei Fenghe already is on record expressing China's willingness to deepen military cooperation with Caribbean countries. Of more concern to US security interests is the ongoing seaport expansion project in the already commercially important port at Kingston, Jamaica, as well as the port at Freeport, Bahamas, China's possible new base of operations 90 miles off the US coast." – Lawrence A. Franklin
London & Brussels Agree To One Last Round Of Trade Talks As Optimism For A Deal Sours – Tyler Durden
Killer robots will make war worse – "There are no winners when lethal violence is consequence-free. I've mentioned Terminator; now I can get on with the article — but it is highly unlikely that future military robots are going to be humanoid-shaped cyborgs. These are only mechanically efficient on rough and broken terrain for one: 'killer robots' are far more likely to be drone-like, or tracked (or swarms of both)." – Mike Martin
The Nexus: "COVID-19, Gig Economy or Expendable Employees" – "COVID-19 has created a situation where everyone's livelihood depends on what regulations the government is going to impose on a given day. One day your employer can function, the next they can't, because someone above you made a decision without consulting you. All you can do to secure your immediate future is try and work out what the government is going to do next, and show what a good person you are by jumping the right way and applauding it. Your employment rights, history with the company, skills and experience are irrelevant. The gig economy, far from freeing people to dip in and out as needed, is worse than wage slavery. You do not know when or if you are getting paid, or if you even have work, or what rates you will be offered or can charge." – Seth Ferris
The Weirdest, Most Distorted Economy Ever – "The Fed is not allowing the economy to heal, but instead induces more distortions and weirdness." – Doug French
The Viral Assault On Small Businesses – "COVID-19 has provided the perfect cover for Schwab's disciples to assault one of America's remaining expressions of freedom and independence: small businesses. With lockdowns, politicians get to pick and choose what businesses survive and what businesses don't. They get to decide who's essential and who isn't." – MN Gordon
More Than Half of New York's Restaurants Are in Danger of Closing: Survey – Erika Adams – THANK YOU, GOV. CUOMO. PERFECT EXAMPLE OF WHAT MR. GORDON WRITES ABOUT IN THE ABOVE LINK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Flee New York If You Can – "New York is falling further down the economic rat hole. Governor Andrew Cuomo's solution is the same as ever, raise taxes." – Mish
Cycles, Systems and Seats in the Coliseum – "The idea that debt, leverage, speculation, greed, exploitation and parasitic elites can expand exponentially forever is magical thinking." – Charles Hugh Smith
Everything Will Come Tumbling Down (VIDEO) with Rick Ackerman – "the write downs starting in 2021 in "commercial real estate, energy, municipal transit systems and insolvent pension finds" (just to name a few) are going to be enormous." – Greg Hunter
Micah 7:4 The best of them is as a brier: the most upright is sharper than a thorn hedge: the day of thy watchmen and thy visitation cometh; now shall be their perplexity.
LYRIC FOR THE WEEK
Boy! Boy!
Now in the street, there is violence
And-and a lots of work to be done
No place to hang out our washing
And-and I can't blame all on the sun
Oh no, we gonna rock down to Electric Avenue
And then we'll take it higher
Oh, we gonna rock down to Electric Avenue
Workin' so hard like a soldier
Can't afford a thing on TV
Deep in my heart, I abhor ya
Can't get food for the kid
Good God, we gonna rock down to Electric Avenue
Ho, we gonna rock down to Electric Avenue
Oh God, we gonna rock down to Electric Avenue
Who is to blame in one country?
Never can get to the one
Dealin' in multiplication
And they still can't feed everyone
Ho no, we gonna rock down to Electric Avenue
Ho, out in the street
Out in the street
Out in the daytime
Out in the night
Out in the playground
In the dark side of town
Hey, we gonna rock down to Electric Avenue
Ohh yeah
Rock it in the daytime
Rock it in the night
Rock it in my…
( Electric Avenue by Eddy Grant )


Services and facilities at the hotel include wireless internet access, a restaurant, a breakfast room and a bar. A garden is among the features contributing to a pleasant stay. Guests travelling in their own vehicles can make use of the available parking spaces.
Special family rooms are available for families with children. Guests will also find a balcony in most rooms. Extra beds can be requested. A TV is among the amenities in all rooms. In each of the bathrooms, guests will find a shower and a hairdryer.


text:
Search Results: Tea Street Band (1254)
Skids release new album ahead of Empire date as Tea Street Band and Average Sex pen Liverpool gigs
Pulled Apart By Horses will play Phase One while Stand Atlantic and Boston Manor announce gigs, Getintothis' Lewis Ridley with a new…
PRS Foundation Momentum Music Fund to support Liverpool musicians, Tea Street Band play Cammell Laird gig and a new track from Profiler
Christine and The Queens will headline All Points East, Bobhowla launches new single at 81 Renshaw and Dub Pistols to…
Tea Street Band, I See Rivers: The Shankly Hotel, Liverpool
As The Tea Street Band play their third home gig within a week, Getintothis' Kevin Barrett took in the sights…
Tea Street Band, TRACKY, Beyond Average: District
Having just returned with a new album, Getintothis' Lewis Ridley was at District as Liverpool legends The Tea Street Band also announced…
Liverpool music gig guide: The Tea Street Band, Hinds, Slaves, Gruff Rhys and more
November's in full swing and with it, so are the gigs, as Getintothis' Simon Kirk has all the details.
The Tea Street Band release new album details: Nick Otaegui talks Liverpool venues, The Maybes?, and Frequency
As The Tea Street Band have release details of their new album and announce a date at District as part of…
Tea Street Band, Silent K, The Shipbuilders: North Shore Troubadour, Liverpool
Hometown heroes, Tea Street Band, take over the north dockside space and Getintothis' Ryan Craig was in attendance to soak it all…
Tea Street Band, Halem, Scarlet, David Barnicle: The Zanzibar, Liverpool
The Tea Street Band return to their old stamping ground, Getintothis' Warren Millar laps up the local heroes return to the…
International Mersey River Festival announces Clean Cut Kid, Louis Berry, Tea Street Band and more for BBC Music Day 2016
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As Merseyside favourites the Tea Street Band returned with a bunch of new tunes ready for action, Getintothis' John Johnson…
Bob Dylan, Neil Young: Hyde Park, London Bob Dylan and Neil Young play to 65,000 fans…
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The Bristol quintet may dislike being associated with "punk" and the negative connotations the term represents, but then, they are a punk band for new times.
It's been a somewhat incredible year for IDLES, who first turned heads in 2017 with their ferocious debut Brutalism, receiving heavy airplay on BBC Radio 6. The band had spent years trying to find their sound and voice, scrapping around with the likes of Slaves finding a new approach to UK punk that dared to traverse into what could conceivably be called pop music.
Indeed, even the more traditional punk scene in the UK has taken issue with the band's success, principally because of that very success 'appropriating' the kinds of messages and sounds they have been promoting for years, just on a much smaller scale. The reaction to IDLES especially since last year's breakout (and our album of the year) record Joy As An Act Of Resistance has been fascinating. The band have been met with either total adoration or admonishment seemingly for exactly the same reasons on either side. No wonder they proclaim themselves to not be a punk band.
So what does distinguish IDLES from their contemporaries? Why do they find themselves up against such derision? Are their detractors right? Well, for one thing, the band at no point have ever claimed to be working class. And they certainly don't claim to be a "punk" band in the traditional sense, merely a "protest" band with a sardonic voice highlighting much of the UK's social issues. The important thing about IDLES is, they write excellent pop songs that carry an important, positive and left-wing social message. Also, the fact that their supposed allies on the same political spectrum can't agree about the band, says a lot about the left in general in the UK.
It is understandable if one does not appreciate IDLES' music for being too aggressive, or from the punk's view not aggressive enough, or if one isn't on the left-wing and therefore do not agree with the band's politics. However, it should not be understated what a powerful movement the guys have created at such a crucial time in their country's history. Millions marched on parliament two weekends ago in a desperate attempt to cease the madness of Brexit, while over 6 million have signed the accompanying petition. It should not come as a surprise if many of the signees have Joy As An Act Of Resistance latest album on their heavy rotation at this point in time.
The band clearly – to this observer at least – come from a passionate and genuine place, one that is unfazed by what others what them to do or be, and instead progresses their pro-immigration (Danny Nedelko), anti-racism, sexism, homophobia message. Their message, which so brilliantly deals with toxic masculinity (Never Fight a Man with a Perm) and male depression (Samaritans) or the catastrophe of Brexit (GREAT), or expresses love and respect to strong women ('Mother').
One only has to look at their riotous live shows, something that the country woke up to thanks to their performance on 'Later with Jools Holland' last year, which we witness tonight on the first of a run of three sold-out nights at Camden's Electric Ballroom. And it's not just trendy, "socially conscious" London that is sold out, it's the entire tour spanning the whole country and beyond into mainland Europe. IDLES may have their critics, but they also have the fans to back it up. Tonight the crowd are singing along to every single word offered by frontman Joe Talbot, an exquisite force of good and bad, depending on what the song requires. At one point the outfit invited, a fan who had earlier shouted for the band's breakout single Well Done and got admonished for it, to the stage to sing the song with them – and to "Daniel's" credit, does an excellent job – and Talbot returns the good-natured feeling amongst this act and their fans. The message is clear: "Love Each Other"!
So while it seemed surprising that The BRIT Awards – a traditionally conservatively pop music affair – singled out IDLES as one of the breakout acts of the UK this year, it makes sense when one witness the positive power they possess over a whole slew of people who otherwise, wouldn't necessarily listen to "punk" music. It was said around 2016 when both Brexit and Donald Trump were elected, that "at least the music will be good" hanging on to an idea that the best music exists at times of protest and conflict. Well, here are IDLES, proving that statement to the hilt. Once their gruelling year-long schedule of presenting their message comes to an end after this summer's festival circuit, we may have a better idea of where the future of the UK lays, given they are now past their Brexit deadline with still no clear indication of what will happen. Whatever that is, Idles will be remembered for their part within it, and will hopefully be around to document what happens next. We need this band in our lives.
IDLES are bringing their furious live show to various stages over the next months, including the 36th Haldern Pop Festival in August, presented by NOTHING BUT HOPE AND PASSION.


Interview with Chad from the Long War playing Sunday night at Live On Elgin.
Thanks for turning me onto Trailer Bride. Great band with great records.
jeb, You are most welome. Swingle rules!
Thanks Martha. See you next week!


"You do not have enough access privileges to sync this iPod"
Discussion in 'iPod' started by Ivan P, Apr 10, 2009.
Starting a few hours ago I've had a really odd iTunes syncing problem. Whenever I connect my iPod it's coming up saying "you do not have enough access privileges to sync your iPod".
I did a search and people seemed to only suggest reinstalling iTunes, making sure you have an admin account, and restoring the iPod. I've tried all of that (by default I have always had an admin account anyway).
I wish I had some advice for you. That seems like a pretty unique problem. I would suggest doing a permissions repair and see if that helps.
Hmm.. try this. Make sure your iPod allows for Disk Use. Go to your desktop, select your iPod and hit Command+I. Scroll down to Sharing & Permissions. Click the "+" sign (unlock the lock, if you have to), choose your User name and click "Select". Now, click the little gear next to the "+ -" boxes, and choose "Apply to Enclosed Items". Then try to sync again in iTunes.


Description: The client targeted to the teen segment of the market for the brand in Romania. The team created an entertaining way to promote sales through an online game with an on-pack promotion. The consumers by texting the on pack code or by submitting it to the microsite gained access to a fun web game. At the same time they were participating to a draw for winning cash prizes!
Results: The campaign made an impression to the targeted segment, increasing the sales of the product and the customer loyalty with an amazing repetitive purchase drive.


text:
\section{Introduction}\label{introduction}

We do not know if there exists a theory of quantum
gravity and precisely how we should think about
quantizing geometry. The amazing successes of quantum
mechanics and quantum field theory have been obtained
in the rigid background of flat spacetime. Can we
extend the realm of quantization to include the geometry
of spacetime itself in a consistent way? Even if the answer is
affirmative (as will be argued
shortly), we are still faced with the problem that
starting out with general relativity (GR) and expanding around a
fixed classical background geometry, the
gravitational fluctuations are non-renormalizable in a
conventional field-theoretical sense.

How should we deal with the non-renormalizable aspects? The logic behind string theory
is in a sense in line with how
non-renormalizable theories have been handled
until now. Two examples in point are the four-fermion model
of the weak interactions and the non-linear sigma model
of pion interactions. In both cases new degrees of freedom were introduced,
which made the more fundamental, underlying field theories
renormalizable. The apparent non-renormalizability of the models was
due to our incomplete understanding of the underlying short-distance
physics. String theory introduces an infinite number of
new field degrees of freedom in order to tame the UV divergences
of the gravitational field. This solution to the
UV problem has a certain elegance, since it can be described as moving from
zero-dimensional point particles to one-dimensional strings in an
(almost) unique way, dictated by relativistic invariance. When
the string is expanded into modes, one is led
to an infinite set of fields. However, despite the presence of
an enormous number of degrees
of freedom string theory has
had difficulties reproducing anything like the universe we observe.
Loop quantum gravity and its
ramifications constitute other attempts to define a theory of quantum
gravity \cite{cambridge}. In loop quantum gravity one insists that holonomies
are quantum objects which are finite. This leads to a somewhat
non-standard quantization with non-separable Hilbert spaces,
and it is in general difficult to show that one obtains
a $\hbar \to 0$ limit which can be identified with classical GR.

The asymptotic safety program \cite{weinberg} tries to address the problem of
non-renormalizability in a more mundane way, using only
ordinary quantum field theory. It appeals to the Wilsonian
concept of renormalizability, where the UV or IR behaviour
of a quantum field theory are linked to the existence of fixed
points of the renormalization group. Accordingly, in this framework
one conjectures that the behaviour of quantum gravity at high energies is governed by a
non-Gaussian fixed point in the UV, which has
properties similar to the Gaussian UV fixed point known from renormalizable
quantum field theories. In a renormalizable theory with a
Gaussian UV fixed point, sufficiently
close to it there are only a finite
number of independent operators that take us away from the fixed point
when we integrate out high-frequency modes. Furthermore, the coupling
constants associated with these operators scale to zero at the fixed point.
For a Gaussian UV fixed point in flat spacetime we can
(except for possible complications with gauge invariance etc.) obtain
the possible operators by power counting. The associated coupling constants
are in principle the only ones that need fine-tuning in order to reach the
fixed point. One can use perturbation theory to check this
picture when one is close to the Gaussian fixed point.
Asymptotic safety assumes that a similar scenario is valid for a putative
non-Gaussian fixed point, the only problem being that we currently
have no examples of such non-Gaussian UV fixed points in four-dimensional
conventional quantum field theory.
Since the fixed point in question is non-Gaussian,
we do not have perturbation theory available to investigate it.
It is nevertheless a logical possibility that
such a fixed point exists precisely in the case of quantum gravity.
Over the last 20 years investigations using improved renormalization
group techniques\cite{exactRG}, as well as 2+$\varepsilon$ dimension
expansions\cite{kawai} have produced some evidence for the existence
of such a UV fixed point  for quantum gravity.

Finally, a simple
way to address the non-renormalizability issue using only conventional
quantum field theory has more recently been suggested by Ho\v rava and
since been dubbed Ho\v rava-Lifshitz gravity\cite{horava}.
It emphasizes unitarity and
the requirement that the theory should be renormalizable. It achieves
this by insisting on at most second-order time derivatives in the action
but allowing for higher-order spatial derivatives. The price one pays
is that the theory violates Lorentz invariance at short distances
where the higher-derivative terms are important, the hope being that --
in agreement with observations --
the Lorentz invariance is approximately restored at large distances.

Causal dynamical triangulations (CDT) is a lattice regularization
of quantum gravity\cite{al,ajl1}.
It provides us with a non-perturbative definition
of the path integral of quantum gravity, where the length of the
lattice links $a$ acts as a UV cut-off. Formally, the
continuum limit is obtained when $a \to 0$. As a lattice theory
it fits naturally into a Wilsonian framework and can therefore
be thought of as an independent way of investigating the asymptotic safety scenario;
one has a phase diagram in terms of the bare coupling constants and
looks for second-order phase transition points which can serve as the
non-Gaussian UV fixed points of asymptotic safety. Having identified
such fixed points one can study the renormalization group flow close
to them. At the same time, CDT is well suited to serve
as a regularization of Ho\v rava-Lifshitz (HL) gravity models,
since both in CDT and HL gravity one integrates in the path integral over
geometries which have a preferred time foliation. As will be discussed below, the CDT
phase diagram also has many similarities with a Lifshitz phase diagram.

Before entering the detailed discussion of CDT results, let us discuss
three key issues:
\begin{itemize}
\item[(1)] Does it make sense to talk about a quantum theory of gravity, which includes
fluctuating geometries, when conventional quantization is always
performed with reference to a fixed geometry?
\item[(2)] Does it make
sense to consider a lattice regularization of a diffeomorphism-invariant theory?
\item[(3)] Does it make sense to
talk about a Wilsonian framework in a diffeomorphism-invariant theory,
where one has not even defined what is meant by a (diffeomorphism-invariant)
correlation length?
\end{itemize}
As it happens, all of the above questions can be answered affirmatively without
addressing the more difficult question of whether there exists a quantum gravity
theory in four-dimensional spacetime. In two dimensions, gravity becomes
a very simple theory, since the integral of the scalar curvature is
topological. Thus there {\it is} no dynamical action. Nevertheless
the theory has a non-trivial partition function, and produces non-trivial amplitudes
for universes with one boundary geometry ``propagating'' into another
boundary geometry and for matter fields living on such fluctuating
geometries. Of course, this theory has no propagating local gravitational
degrees of freedom. However, the conceptual questions mentioned above
do not really refer to the propagation of gravitational degrees
of freedom, but to the fact that we are dealing with fluctuating
geometry, in a setting where we only want to ask diffeomorphism-invariant questions.
Viewed in this perspective, one could even say that the two-dimensional theory provides us
with the ultimate test, since there hardly {\it is} any classical action (only
the cosmological term). If we think about the quantum theory using
the path integral as a sum over spacetime histories, we are dealing with a
situation that is ``maximally quantum", in the sense that each configuration
in the path integral has the same
weight. This corresponds formally to the limit
$\hbar \to \infty$, i.e.\ the ultimate quantum limit.

So-called 2d Liouville quantum gravity can be solved analytically,
both using canonical quantization and the path integral. It {\it is}
the quantum theory of fluctuating two-dimensional geometries with fixed topology,
and therefore answers (1) above. The same theory can be regularized using lattices,
using the formalism called ``dynamical triangulations'' (DT). In it
one performs the path integral in the Euclidean sector
by using equilateral triangles as building blocks, and gluing them
together in all possible ways compatible with the given topology. In this
way the path integral becomes the sum over a class of piecewise linear
geometries, whose geometry is determined entirely by the way the building
blocks are glued together, justifying the name ``dynamical triangulations''.
The link length $a$ of the building blocks acts as a UV cut-off.
Somewhat surprisingly, one can solve this lattice theory analytically
and in the limit $a\to 0$ recover the continuum quantum Liouville
results. In other words, there exists a lattice regularization where one
sums over spacetime {\it geometries} (as opposed to spacetime {\it metrics}),
no gauge-fixing is needed (and therefore no issue of diffeomorphism-invariance
arises), and the $a \to 0$ limit leads to
a diffeomorphism-invariant theory, namely, quantum Liouville theory.

The lattice theory also fits beautifully into a Wilsonian framework,
thereby answering question (3) above. To start with, it has {\it universality} in
the sense that we are not restricted to using equilateral triangles
as building blocks. Using instead almost any ensemble of polygons with
side-length $a$, and gluing them together with almost any positive weights,
the continuum limit $a\to 0$ will still be the same. By adding
suitable higher-curvature action terms to this theory of planar graphs
one again obtains the same continuum limit, demonstrating
a Wilsonian universality with respect to both regularization and the choice
of action.

Finally, is it possible
to define the concept of diffeomorphism-invariant correlators depending
on a diffeomorphism-invariant correlation length? In two dimensions, where we
have no propagating gravitational field degrees of freedom, one has
to add matter fields to the fluctuating geometries to answer this
question. This can be done, and the answer is again in the affirmative
\cite{correlators}. To be more explicit, let us consider a matter field
$\phi(x)$, whose dynamics is governed by some diffeomorphism-invariant
action. Clearly it makes no sense to
consider the correlation between two local fields $\phi(x)$ and $\phi(y)$, since $x$ and
$y$ are just coordinates. In addition, since the geometry of spacetime
is fluctuating, the geodesic distance between $x$ and $y$ will depend
on the geometry, and we are summing over these geometries. How
{\it do} we then define a meaningful diffeomorphism-invariant correlation between fields?
In flat $d$-dimensional spacetime, let us rewrite the correlator of
the scalar field $\phi(x)$ in the form
\begin{equation}\label{h7}
\langle \phi \phi (R) \rangle_V \equiv
\frac{1}{V} \;\frac{1}{s(R)} \int {\cal D} \phi\, e^{-S[\phi]}
\int\!\! d^dx \!\int \!\! d^dy
\;  \phi(x) \phi(y)
\;\delta(R \!-\! |x-y|).
\end{equation}
As indicated, this expression depends on a chosen distance $R$,
but no longer on specific
points $x$ and $y$, which instead are integrated over.
The integrand can be read
``from right to left" as first averaging
over all points $y$ at a distance $R$ from some fixed point $x$, normalized
by the volume $s(R)$ of the spherical shell of radius
$R$, and then averaging
over all points $x$, normalized
by the total volume $V$ of spacetime.
We assume translational and
rotational invariance of the theory and that $V$ is so large that
we can ignore any boundary effects related to a finite volume.
This definition of a correlator is of course non-local, but unlike
the underlying locally defined correlator has a straightforward
diffeomorphism-invariant
generalization to the case where gravity is dynamical, namely,
\begin{eqnarray}
\langle \phi \phi (R) \rangle_V &\equiv&
\frac{1}{V}\int {\cal D} [g]\, \int {\cal D}_{[g]} \phi \;\mbox{e}^{-S[g,\phi]}
\;\delta\Big(V-\!\!\int \!\! d^dx \sqrt{\det g} \Big)\times \nonumber \\
&&
\int\!\! d^dx \!\int \!\! d^dy\, \;\frac{\sqrt{\det g(x)} \,
\sqrt{\det g(y)}}{s_{[g]}(y,R)}
\; \phi(x) \phi(y)
\;\delta(R \!-\! D_{[g]}(x,y)),
\label{h8}
\end{eqnarray}
which now includes a functional integration over
geometries. The geometry corresponding to a metric $g_{ij}$
is denoted by $[g]$ and the
dependence of the action, measures, distances and volumes refers
to the specific geometry $[g]$, which is finally integrated over,
but with $R$ and $V$ kept fixed.
It can be shown that this definition allows us to think about
correlators in the standard way. Most importantly in this
context is the fact that the Wilsonian concept of a divergent correlation
length when approaching a second-order phase transition --
key to the universality of the continuum limit -- is still true
when integrating over fluctuating geometries\cite{correlators}.

\section{Causal Dynamical Triangulations}

\begin{figure}[t]
\centerline{\includegraphics[width=4in]{4dsimplices.eps}}
\caption{A triangulation in CDT consists of four-dimensional triangulated
layers assembled from (4,1)- and (3,2)-simplices, interpolating between
adjacent integer constant-time slices (left), which in turn are triangulations
of $S^3$ in terms of equilateral
tetrahedra. Each purely spatial tetrahedron at
time $t$ forms the interface between two
(4,1)-simplices, one in the interval $[t-1,1]$,
and the other in $[t,t+1]$, as
illustrated on the right. Although a
(3,2)-simplex shares none of the five tetrahedra on its
surface with a constant-time slice
(the tetrahedra are all Lorentzian), it is nevertheless
needed in addition to the (4,1)-building block to obtain
simplicial manifolds with a well-defined causal structure.}
\label{fig1}
\end{figure}

The CDT lattice regularization differs in a crucial way from the
DT lattice regularization discussed in the Introduction.
While it uses the same action (the discretized Einstein-Hilbert action,
in the form of the so-called Regge action\cite{regge})
as DT, it uses only triangulated manifolds with the topology of a direct
product $[0,1]\times {}^3\Sigma$, and subject to a preferred
proper-time foliation in the time direction.
The motivation for this is twofold. While DT is
inherently Euclidean in its set-up, CDT is an attempt to define the
regularized path integral in spacetimes with Lorentzian signature.
Following earlier ideas\cite{teitelboim}
we insist on including in the path integral
only  locally causal geometries, whose light cone structure
is everywhere non-degenerate.
CDT is an attempt
to implement such a path integral, defined as  a
lattice regularization, much in the same way as was done using DT.
(We refer the reader to a comprehensive recent
review \cite{physrep} for details.) Like the DT geometries, the  CDT geometries
are piecewise linear geometries constructed by gluing together a few
standard building blocks, but such that they respect the proper-time
foliation. In this construction we have space-like lattice links,
to which we assign a length $ds^2 = a_s^2= a^2$,
and time-like lattice links, to
which we assign a proper-time length $ds^2= a^2_t = -\a a^2$, where
$a$ and $a_s$ are positive. This is illustrated in Fig.\ \ref{fig1}
in the case of four-dimensional spacetime, where four standard building
blocks are needed, the so-called (4,1)- and (3,2)-building blocks
shown in the figure and time-reversed (1,4)- and (2,3)-building
blocks, the numbers referring to the number of vertices of the four-dimensional
simplex at spatial slice $t$ and spatial slice $t+1$. The spatial slice at any
$t$ is assumed to have the topology ${}^3\Sigma=S^3$ (we assume that space is
compact, and have chosen the simplest topology), and is triangulated
in terms of equilateral tetrahedra of link length $a_s$. At discrete times $t$ and $t+1$
we thus have two purely spatial triangulations of $S^3$. Fig.\ \ref{fig1} illustrates
how to fill in the four-dimensional ``slab'' between the two $S^3$-triangulations
with four-simplices,
preserving the topology $[0,1]\times S^3$. In the path integral
we will sum over all triangulations of the three-sphere at $t$, all triangulations
of the three-sphere at $t+1$, etc.,
and over all four-dimensional triangulations of the slabs
compatible with the given choices of the spherical triangulations at $t$,
$t+1$, $\dots$ . For each spacetime geometry thus obtained we
can perform a rotation to Euclidean signature by rotating
$\a$ from positive to negative values in the lower-half complex plane.
The corresponding Regge action also rotates in the way expected
for a rotation from Lorentzian to Euclidean signature, that is,
\begin{equation}\label{j1}
i S_L(\a) = -S_E(-\a).
\end{equation}
The constraint of local causality is not a topological constraint, and
after rotation to Euclidean signature leads to a summation
over a restricted class of Euclidean geometries. The corresponding theory
is therefore potentially different from
``Euclidean quantum gravity'' \`a la Hawking. This brings
us to the second motivation for replacing the DT
with the CDT regularization in spacetime dimensions $d$ larger
than two. If one restricts oneself to the
Euclidean Einstein-Hilbert action in Regge form, the DT lattice theory
has no continuum limit. Studying the theory with Monte Carlo simulations,
one finds a phase transition as a function of the bare
gravitational coupling constant, but it is of first order.
Such a first-order transition cannot be used
to define a continuum quantum field
theory. As discussed in the Introduction, we need a second-order transition
to which we can associate a divergent correlation length.
The situation will be different when we use the CDT regularization.

\section{CDT phase structure}

We will discuss here the four-dimensional CDT theory. We rotate it
to Euclidean signature as described above. Because the four-dimensional theory
cannot be solved
analytically, we need to rotate it to Euclidean signature to be able to study it
by Monte Carlo simulations.

Let us first write down the regularized Euclidean Einstein-Hilbert action
for a CDT configuration. As mentioned earlier, we use the so-called
Regge action, which can be used for
any piecewise linear geometry. For a $d$-dimensional
triangulation the curvature will be located at  the $(d-2)$-dimensional
subsimplices, which implies that in four dimensions the curvature
is concentrated at the two-dimensional subsimplices (the triangles).
In the case of CDT the Regge action becomes exceedingly
simple, because we are using fixed building blocks to construct the
geometries. The curvature depends only on how we glue
these building blocks together. After using various identities relating
the number of subsimplices and the order of vertices, links and
triangles, the action will only depend on the total number $N_0$ of vertices,
the total numbers $N_4^{(4,1)}$ and $N_4^{(3,2)}$ of (4,1)- and (3,2)-simplices
and the parameter $\a$,
\begin{eqnarray}\label{h19}
S_E[-\a;T] &=& -(\kappa_0+6 \Delta)N_0(T) +
\kappa_4\Big(N_4^{(3,2)}(T)+N_4^{(4,1)}(T)\Big)  \\
&& + \Delta \Big(N_4^{(3,2)}(T)+2N_4^{(4,1)}(T)\Big),
\nonumber
\end{eqnarray}
where the asymmetry parameter $\Delta$ \index{Asymmetry Parameter $\Delta$}
is a function of $\a$ such that $\Delta(\a\!=\! 1) =0$.
In this formula $\kappa_0 \propto 1/G_0$, the bare inverse gravitational coupling
constant, while $\kappa_4$ can be more or less identified with $\Lambda_0/G_0$,
$\Lambda_0$ being the bare cosmological coupling constant. The CDT partition
function is given by
\begin{equation}\label{j4}
Z(\kappa_0,\kappa_4,\Delta)= \sum_T \mbox{e}^{-S_E[T]},
\end{equation}
where one sums over four-dimensional CDT triangulations of the
kind described in the previous Section. We should point out that
formula \rf{j4} contains a small subtlety. In the first place, one would
not consider $\Delta$ as a coupling constant. It was merely
chosen to parametrize the asymmetry between the links in spatial and temporal
directions, but the classical Einstein-Hilbert action was adjusted
precisely to take this into account. However, it turns out
that in the region of bare coupling-constant space where
we observe a potentially interesting phase structure, the {\it entropy}
of  configurations with the same action is as important as
the action itself\footnote{By entropy we here simply mean the
relation $S = \ln ({\rm number~of~configurations})$.}.
Although the entropy is independent of
$\Delta$, the real quantum effective action becomes in this way
a function of $\Delta$. In the classical limit the contribution of the (bare) action
will always be much more important than the entropy term, simply because
the action is multiplied by $1/\hbar$, while this is not the case
for the entropy term. However, the interesting Planckian physics we observe is
of course {\it not} in this semiclassical limit. It follows that we
have a theory depending on
{\it three} coupling constants, $\kappa_0$, $\kappa_4$ and $\Delta$.
For technical convenience,  we keep the four-volume fixed during
the Monte Carlo simulations, which effectively removes $\kappa_4$ as a
coupling constant. We are thus left with two coupling constants, $\kappa_0$ and $\Delta$.

The numerical set-up is as follows: we choose a four-volume
(the discrete number of four-simplices) and a large proper-time extent $t$ (the discrete number
of lattice time steps), and perform the Monte Carlo simulations
for a given choice of $\kappa_0$ and $\Delta$. We can measure the
three-volume distribution as a function of proper time $t'$ between 0 and $t$, and deduce
from the measurements that there are
three qualitatively different types of  three-volume profiles $N_3(t')$,
depending on the choice of $\kappa_0$ and $\Delta$. Here $N_3(t')$ denotes
the number of tetrahedra forming a triangulation  of the
spatial slice at time $t'$. The different profiles correspond
to different phases, which we have denoted by A, B and C \cite{ABC}.
The corresponding phase diagram
is shown in Fig.\ \ref{fig2} (we refer to elsewhere\cite{phasediagram} for details).
\begin{figure}[t]
\centerline{\includegraphics[width=4in]{Fig17.eps}}
\caption{The phase diagram of four-dimensional CDT.}
\label{fig2}
\end{figure}
In phase B we observe a {\it collapse} of the four-dimensional universe
to a three-dimension one, in the sense that all of the three-volume
$N_3(t')$, $t'\in [0,t]$, is located at a {\it single} time.
The situation in phase A is completely opposite. The three-volume $N_3(t')$ is
spread out over the whole time interval $[0,t]$, and the magnitude of $N_3(t')$
is close to being a random variable, with little correlation with the neighbouring
three-volumes $N_3(t'+1)$ and $N_3(t'-1)$ (at least, the correlation is rather short-ranged).
Finally, in phase C the situation is again very different. There is no
collapse of three-volume around a single spatial slice. Instead, the three-volumes $N_3(t')$
at adjacent times are highly correlated, resulting in a genuinely
four-dimensional universe. The universe
has a definite extension in the time direction, independent of the choice of $t$, as long as
$t$ is sufficiently large compared to the given choice of $N_4$. Along the
remainder of the $t$-axis one finds only vanishing three-volume (to be precise, one finds
three-volumes which are close to the minimal cut-off size of 5 tetrahedra, since we
do not allow the computer algorithm to shrink the three-volume to strictly
zero). The actual time extension of the universe depends on the
chosen $N_4$ and scales proportional to $N_4^{1/4}$ as one would na\"ively expect.
Similarly, the non-zero three-volumes $N_3(t')$ scale proportional to  $N_4^{3/4}$.
This is the reason why we claim that the universe is four-dimensional\cite{ABC}.
At first sight it may seem a triviality that
the universe should scale in this fashion,
but it is in fact highly non-trivial. Although the elementary
building blocks are four-dimensional, nothing tells us that
they will line up to form a four-dimensional object with
approximately $N_4^{1/4}$ building blocks in each
direction. Since absolutely no ``background'' geometry has been put
in by hand to ensure the four-dimensionality of the resulting ``quantum spacetime",
this will in general not happen at any scale, as exemplified by the situation in phases A and B.
Furthermore, as we have already noted and
as will be discussed later, in phase C we are far from any choice
of the bare coupling constants where the classical action dominates.

We thus have identified three phases with very different geometric large-scale characteristics.
Associated with these phases are phase transition lines, as shown in Fig.\ \ref{fig2}.
We have investigated the order of these transitions, with the result
that the transition A-C is first order, while the transition B-C
is second order\cite{jordan}.
(We are currently not particularly interested in the transition
A-B, since geometry in neither phase A nor B seems relevant as
a model for a four-dimensional universe.)
\begin{figure}[t]
\centerline{\includegraphics[width=4in]{Fig01xxx.ps}}
\caption{A typical three-volume profile (and the average profile)
for some choice of coupling constants in phase C.}
\label{fig3}
\end{figure}

Following the Wilsonian logic on how to take the continuum limit,
our main interest will be focused on the B-C phase transition line. Can it
be used to define a UV limit of quantum gravity? Before addressing this
point, we will take a closer look at the situation in phase C, where
we seemingly observe four-dimensional universes.

\section{The physics of phase C}

A typical three-volume profile in phase C is shown in Fig.\ \ref{fig3}.
Fig.\ \ref{fig4} highlights the average value of the
profile and the size of typical fluctuations. The data are
collected for fixed values of the coupling constants and
fixed $N_4$. For the average profile there
is a perfect scaling $\propto N_4^{3/4}$ of the height and $\propto N_4^{1/4}$
of the width of the profile. However, the fluctuations
of the height of the profile
scale like $N_4^{1/2}$. This means that for fixed values of the bare
coupling constants, taking $N_4\to \infty$, the relative fluctuations
will go to zero and we will have a well-defined limit.
For fixed values of the bare coupling
constants, the average profile can be fitted perfectly to the formula
\begin{equation}\label{h24}
 \langle N_3(i)\rangle  \propto
N_4^{{3}/{4}}
\cos^3 \left(\frac{i}{s_0 N_4^{1/4}}\right),
\end{equation}
where $i$ denotes (integer) lattice time, $N_4$ the total
number of four-simplices\footnote{For fixed values
of the coupling constants, we can use for $N_4$ either the total number
of four-simplices or the total number $(4,1)$-simplices, say. The numbers
will be proportional, the constant of proportionality changing
somewhat with the coupling constants $\kappa_0$ and $\Delta$.}
and $N_3(i)$ the number of tetrahedra
at time $i$ \cite{s4a}, and $s_0$ is a constant
which will depend on the choice of bare coupling constants
(the formula is of course not valid in the ``stalk'', where
$N_3(i) \approx 5$.).
\begin{figure}[t]
\centerline{\includegraphics[width=4in]{Fig24.eps}}
\caption{The average three-volume profile and the fluctuations
for $N_4= 360.000$, at $\kappa_0=2.2$ and $\Delta=0.6$.}
\label{fig4}
\end{figure}

Can the functional form of the expectation value found in \rf{h24} be obtained
directly from an action principle? The answer is yes \cite{semi}.
The minisuperspace approach
to quantum gravity by Hartle and Hawking\cite{hawking}, which only involves
the scale factor of the universe (equivalently, the three-volume)
reduces the Einstein-Hilbert action to the
``effective'' action
\begin{equation}\label{h25}
S_{\mathit ef\! f}= -\frac{1}{24\pi G} \int d t
\left( \frac{ \dot{V_3}^2(t)}{V_3(t)}+k_2 V_3^{1/3}(t)
-\lambda V_3(t)\right),
\end{equation}
where $t$ denotes proper time, $k_2$ is a numerical constant
and $\lambda$ is a Lagrange multiplier ({\it not} a cosmological constant),
because the total four-volume $V_4$ is kept fixed in the simulations.
The classical solution of the equations of motion
corresponding to $S_{ef\! f}$ is precisely
the $\cos^3 (t/V_4^{1/4})$ referred to in eq.\ \rf{h24}.

From the computer simulations and the measurements of
$\langle N_3(i) \rangle$ and $\langle N_3(i)N_3(j) \rangle$ it is possible
to reconstruct the effective discretized action leading
to \rf{h24}. It has the form\cite{s4a}
\begin{equation}\label{h26}
S_{discr} =
k_1 \sum_i \left(\frac{(N_3(i+1)-N_3(i))^2}{N_3(i)}+
\tilde{k}_2 N_3^{1/3}(i)-\tilde{\lambda} N_3(i)\right).
\end{equation}
This is precisely the discretized version of \rf{h25}, {\it
except for an overall sign}. This overall sign does not affect the
equations of motion derived from the actions, but it shows that in phase C
we are far away from any semiclassical limit, even if the
effective outcome (the average universe) is similar. Since the effective
action \rf{h26} comes from combining the discretized, bare Einstein-Hilbert action
and the entropy of configurations, as discussed earlier, it is clear
that entropy plays an important role in phase C.

Finally, from the effective action \rf{h26}, and comparing to \rf{h25},
it is natural to consider $k_1$, which we can actually measure,
as the dimensionless coupling constant
\begin{equation}\label{j10}
k_1 \propto  a^2/G(a),
\end{equation}
where we have assumed a scale-dependence of the gravitational
coupling constant $G$, using as scale parameter the lattice
cut-off $a$.
In the asymptotic safety scenario, $k_1$ should run to a constant
different from zero when we approach a non-trivial UV fixed point,
while it should go to zero in the IR, where $G(a) \to G$, the ordinary
gravitational coupling constant. We have measured $k_1(\kappa_0,\Delta)$, and there
is a clear indication that it goes to zero when we keep $\Delta$ fixed and
increase $\kappa_0$, moving in phase C towards phase $A$. Similarly, there
is some evidence that $k_1(\kappa_0,\Delta)$ does not go to zero when
we approach the B-C phase transition line moving in phase C,
keeping $\kappa_0$ constant while decreasing $\Delta$. This points to the B-C line
being associated with UV physics. We will now discuss this further
by studying {\it lines of constant physics} in phase C.

\section{Renormalization group flow}

The renormalization group equation in terms of
the dimensionless gravitational coupling constant
${\hat{G}}(a) \propto 1/k_1(a)$ reads
\begin{equation}\label{h29}
 G(a) = a^2 {\hat{G}}(a),~~~~ a \frac{\d {\hat{G}}}{\d a} = -\b({\hat{G}}),~~~~
\b({\hat{G}}) = 2{\hat{G}} -c {\hat{G}}^2 +\dots\; .
\end{equation}
The $\b$-function is assumed to have a non-trivial zero
(if we ignore the dots, which signify higher-order contributions,
it is at ${\hat{G}}^* = 2/c$).
Close to the fixed point we can write
\begin{equation}\label{h30a}
{\hat{G}}(a) = {\hat{G}}^* - K a^{\tilde{c}},~~~k_1(a) = k_1^* + \tilde{K} a^{\tilde{c}},
\end{equation}
for some $K$, $\tilde K$, where the approach to the fixed point is governed by
the exponent
\begin{equation}\label{h30b}
{\tilde{c}}=-\b'({\hat{G}}^*).
\end{equation}
In a  standard lattice theory one would now relate
the lattice spacing near the fixed point to the bare coupling constants
with the help of some correlation length $\xi$.
As we have already discussed, the concept of a correlation length
makes perfect sense even in a theory of fluctuating geometries
(see eq.\ \rf{h8} for a  definition of a diffeomorphism-invariant
correlator). Having such a correlation length available would allow us
to define a path of constant physics when we change the bare coupling
constant (denoted by $g_0$), namely,
by insisting that the correlation length $\xi(g_0)$,
expressed as the number of lattice spacings times the lattice length $a$,
represents a physical length, which is constant when we approach the
fixed point $g_0^*$ where $\xi(g_0)$ diverges. Typically one has
\begin{equation}\label{j30}
\xi(g_0) = \frac{c}{|g_0-g_0^*|^\nu},~~~{\rm i.e.}~~~
a(g_0) \propto |g_0-g_0^*|^\nu,
\end{equation}
thus determining how we should scale the lattice spacing to zero
as a function of the bare coupling constant $g_0$.
However, in four-dimensional
quantum gravity without matter we do not yet have a
suitable correlation length at our disposal which could play this role.
In search of an alternative,
let us first consider the equation $V_4 = N_4 a^4$, which defines
the dimensionful continuum four-volume
$V_4$ in terms of the number $N_4$ of four-simplices and the lattice
spacing. If we could
consider $V_4$ as fixed, we could replace the $a$-dependence of \rf{h30a} by a
$N_4$-dependence, with the advantage that $N_4$
is a parameter we can straightforwardly control.
Re-expressing eq.\ \rf{h30a} in terms of $N_4$ yields
\begin{equation}\label{h31}
k_1(N_4) = k_1^* -K' N_4^{-{\tilde{c}} /4},
\end{equation}
for some $K'$. Since we can measure $k_1$, we could
determine the flow to the fixed point.

In order to apply \rf{h31}, we need to ensure that
we can consider $V_4$ as fixed when we change $N_4$.
For each value of coupling constants and each
value $N_4$ one has a three-volume profile like the one shown
in Fig.\ \ref{fig4}.
Let us be more specific and rewrite \rf{h24} as
\begin{equation}\label{j31}
N_3(i) = \frac{3}{4\omega} {\tilde{N}}_4^{3/4} \cos^3
\left( \frac{i}{\omega{\tilde{N}}_4^{1/4}} \right),
\end{equation}
and for the fluctuations
\begin{equation}\label{j32}
\delta N_3(i) = \gamma {\tilde{N}}_4^{1/2} F\left(  \frac{i}{\omega{\tilde{N}}_4^{1/4}} \right),
\end{equation}
where ${\tilde{N}}_4$ is the number of four-simplices of type (4,1) (and
by construction the total number of tetrahedra contained in the spatial slices),
and where $F(t)$ is a function we have measured\cite{s4a}.
${\tilde{N}}_4$ is on average proportional to the total number of four-simplices,
the constant of proportionality depending somewhat on the choice of
bare coupling constants, as already noted. $\gamma$ and $\omega$ depend
on the bare coupling constants $\kappa_0$ and $\Delta$. We can now write
\begin{equation}\label{j32a}
\frac{\delta N_3(i)}{N_3(i)} = \frac{4\gamma \omega}{3 {\tilde{N}}_4^{1/4}} \;
\left(\frac{F(i/(\omega{\tilde{N}}_4^{1/4}))}{\cos^3(i/(\omega{\tilde{N}}_4^{1/4}))}\right).
\end{equation}

Well away from the phase transition boundaries, our measurements
show that $\omega$ and $\gamma$ are independent of ${\tilde{N}}_4$, when ${\tilde{N}}_4$ is
not too small. Thus, increasing ${\tilde{N}}_4$ while {\it staying}
at a specific point $(\kappa_0,\Delta)$ in phase C does {\it not}
correspond to keeping $V_4$ fixed,
because during this process the size of the
quantum fluctuations in the three-volume decreases
relative to the expectation value of the three-volume according to
\begin{equation}\label{j50}
\frac{\delta N_3}{N_3} \propto \frac{1}{{\tilde{N}}_4^{1/4}}.
\end{equation}

It is a reasonable requirement for a continuum limit
that the ratio \rf{j32a} be independent of ${\tilde{N}}_4$ for
fixed $i/(\omega {\tilde{N}}_4^{1/4})$. Thus, if we
start at a given ${\tilde{N}}_4^{(0)}$, using coupling constants $\kappa_0(0)$ and $\Delta(0)$,
and change ${\tilde{N}}_4$, we have to change $\kappa_0$ and $\Delta$ such that
\begin{equation}\label{j51}
\gamma(\kappa_0,\Delta) \, \omega(\kappa_0,\Delta) =
\gamma(\kappa_0(0),\Delta(0)) \, \omega(\kappa_0(0),\Delta(0))\;
\frac{{\tilde{N}}_4^{1/4}}{({\tilde{N}}_4^{(0)})^{1/4}}
\end{equation}
holds. We can measure $ \omega(\kappa_0,\Delta)$ and $\gamma(\kappa_0,\Delta)$ in phase C,
and have done so, but eq.\ \rf{j51}  is not sufficient to determine a curve
$(\kappa_0({\tilde{N}}_4),\Delta({\tilde{N}}_4)$. We  need another condition. It is
tempting to choose as a second condition that $\omega(\kappa_0,\Delta)$ stay
constant along a curve of constant $V_4$. This requirement implies
according to \rf{j31} that all three-volume profiles along the
curve can be scaled to coincide by identical scaling in ``time'' and
``space'' directions, something which is compatible with our
intuitive understanding of what it means to have constant $V_4$.
The requirement that $\omega(\kappa_0,\Delta) = \omega(\kappa_0(0),\Delta(0))$
determines a curve starting at $(\kappa_0(0),\Delta(0))$. Moving
along this curve, eq.\ \rf{j51} determines the
relationship between $\gamma$ and ${\tilde{N}}_4$ according to
\begin{equation}\label{j52}
\gamma(\kappa_0({\tilde{N}}_4),\Delta({\tilde{N}}_4)) = \gamma(\kappa_0(0),\Delta(0)) \;
\frac{{\tilde{N}}_4^{1/4}}{({\tilde{N}}_4^{(0)})^{1/4}},
\end{equation}
{\it provided} it can be satisfied.

In Fig.\ \rf{fig5} we show the lines of constant
$\omega$ as functions of $\kappa_0$ and $\Delta$, superimposed
on a contour plot of $\gamma(\kappa_0,\Delta)$. If
we start out some distance from the B-C phase boundary, the
plot indicates that it is impossible to
flow to the B-C transition line along lines of constant $\omega$ with
increasing ${\tilde{N}}_4$.
\begin{figure}[t]
\centerline{\includegraphics[width=4in]{strips-width_a.ps}}
\caption{The flow diagram in phase C. The flow lines correspond to
constant $\omega$ in eq.\ \rf{j31} (black lines). The contour plot
refers to the change of $\gamma$ ($\gamma$ increases going from the blue to the
red region). }
\label{fig5}
\end{figure}
However, the situation changes
as we move closer to the B-C phase transition line. The lines
of constant $\omega$ now seem to be directed towards the
triple point. In addition, the increase of $\gamma$ is maximal
when we move in the same direction towards the triple point.
Thus there is the tantalizing possibility that we can have paths of
constant physics leading to the triple point, with \rf{j52}
satisfied when moving along the path.

While the condition $\omega= const.$ may seem a reasonable requirement
to impose for constant $V_4$, we are not forced to adopt it. One can
even argue that one should not use it. The reason is that $\omega$
changes as a function of the bare coupling constants $\kappa_0$ and $\Delta$.
Its main dependence is on $\Delta$, and $\omega$ goes to zero
when we approach the B-C phase transition line by decreasing
$\Delta$ (within measuring accuracy). We thus have two options:
if we regard the change in $\omega$ as reflecting a change in our
universe, the universe contracts
in the time direction when we approach the B-C line. In order
to obtain a finite  {\it continuum} time extent at the transition
line one may therefore have to scale time and space with different
powers of the cut-off $a$ when approaching
the B-C line. This leads naturally to a Ho\v rava-Lifshitz scenario, which we
will discuss in the next Section.

Alternatively, one could adopt
the viewpoint that all universes of the form \rf{j31}
can be identified if we are allowed to rescale time relative
to space by some constant that depends on the bare coupling constants.
Such a freedom implies that we are not taking literally the microscopic
identification of proper time as the number of lattice steps
in the ``time'' direction times $a_t$, the lattice
spacing in the time direction, but only claim that it is
{\it proportional} to the ``real'' proper time.
Thus we are not forced to take a path of constant $\omega$ to
consider $V_4$ constant. However, as mentioned above, it leaves us short of
one condition if we want to determine a path in
the coupling constant space corresponding to what we call
constant $V_4$.

\section{Relation to Ho\v rava-Lifshitz gravity}\label{hlgravity}

As we have described above, CDT provides a non-perturbative
lattice regularization for a quantum theory of geometries,
characterized by the presence of a preferred time foliation\footnote{Note that
recent work \cite{jordanloll} indicates that the strict time foliation may be relaxed, if at the
same time local causality is maintained.}.
In the Euclidean sector one can prove that
the lattice theory has a transfer matrix which is
reflection-positive\cite{ajl1}. One would therefore expect that a continuum
theory obtained from the lattice theory will have a unitary
time evolution.

The features just mentioned resemble those imposed in Ho\v rava-Lifshitz
gravity \cite{horava}. This suggests that CDT can provide a lattice regularization
of quantum Ho\v rava-Lifshitz gravity. Indeed, in the simplest
case of two space-time dimensions, one can prove that CDT
coincides with so-called quantum projectable HL gravity \cite{2dhl}
with at most quadratic derivative terms.
Of course, the situation in two dimensions is rather special. Although 1+1 dimensional
CDT has a preferred
time foliation, it is related to standard two-dimensional Euclidean
quantum gravity (Liouville quantum gravity) in a simple way \cite{al,ackl}.
CDT is the ``effective'' theory obtained from Liouville
quantum gravity by integrating out all Liouville quantum gravity
``baby universes". As a consequence, the amplitudes of the two theories
are related by a simple (non-analytic) mapping between their respective coupling
constants.

In higher dimensions, Ho\v rava's idea was to introduce
higher-derivative terms in the spatial directions to render the
theory renormalizable, while having only second-order time
derivatives to ensure unitarity. Unlike
HL gravity, CDT does not introduce explicit higher-order
derivative terms in the spatial directions. However, as
already mentioned, since entropic terms are important,
it may be that such higher-derivative terms are present
in the effective CDT action. It is conceivable that for some choices of
bare coupling constants CDT provides us with a regularization
of quantum general relativity, while for others it
is a regularization of quantum HL gravity.

The CDT phase diagram presented in Fig.\ \ref{fig2}
has a striking similarity to a Lifshitz phase diagram, as
noticed already elsewhere\cite{phasediagram,horavacqg}. Even the characteristics of the phases
A, B and C can be described in a language similar to the one used
for a magnetic Lifshitz system (details can be found in earlier work \cite{phasediagram}).

When we move towards the second-order phase transition line B-C,
we observe a contraction of the quantum universe in the time direction.
This is in agreement with the fact that we have a second-order transition and that
the universe in phase B collapses to a single time slice.
It indicates that in order to obtain a genuine
continuum limit when approaching the B-C line, one may have to scale
time and space differently, a characteristic feature of HL gravity too.
Various possible isotropic and anisotropic relations between
space and time have been discussed \cite{phasediagram}.

Can the average quantum
universe we observe on the computer  be understood as a HL universe
rather than a universe coming from the effective GR minisuperspace
action \rf{h25}? In the context of HL gravity, one can also derive
a minisuperspace action\cite{elias}, namely,
\begin{equation}\label{mini}
S_{mini} = \frac{2 \pi^2}{16\pi G} \int \d t \; a(t)^3 \Big( 3(1-3\lambda)\
\frac{\dot{a}^2}{a^2} -\gamma\ \frac{6}{a^2} +2 \Lambda+ {\tilde{V}}(a)\Big),
\end{equation}
where we have used the scale factor $a(t)$ instead of $V(t) \propto a(t)^3$. The
parameters $\lambda$ and $\gamma$ are equal to 1 in the case of ordinary
general relativity, but can be different from 1 in HL gravity, and define the IR limit of HL gravity.
The potential ${\tilde{V}}(a)$ contains inverse powers of the scale factor $a$ coming from possible
higher-order spatial derivative terms.

Our reconstruction of the effective action from the computer data
is compatible with the functional form \rf{mini} of the minisuperspace action.
If we were able to extract the constant $\tilde{k}_2$
in front of the potential term in
\rf{h26}, it would enable us to fix the ratio $(1-3\lambda)/2\gamma$
appearing in \rf{mini} \cite{s4a,semiclassical}.
At this stage, the precision of our measurements is insufficient to do so.
The same is true for our attempts to determine ${\tilde{V}}(a)$ for small values
of the scale factor, which is important for understanding
UV quantum corrections to the potential near $a(t)=0$.

\section{Summary}

CDT was born as an attempt to formulate a non-perturbative
path integral directly in spacetimes with Lorentzian signature.
It can be rotated explicitly to Euclidean signature, a necessity if
one wants to use Monte Carlo simulations to study the non-perturbatively
defined theory of fluctuating geometries. Like the ADM formalism, the Lorentzian formulation
introduces an asymmetry between space and
time. This asymmetry survives after rotation to Euclidean signature,
and can potentially make the theory different from so-called Euclidean
quantum gravity. CDT rotated to Euclidean signature has a positive
definite transfer matrix and thus a unitary time evolution when
the theory is rotated back to Lorentzian time. Both
the set-up with a preferred (proper) time and the resulting unitarity
are reminiscent of the starting point of HL gravity in the continuum. The CDT
formalism can be used as regularization of a quantum HL gravity theory, something
which has already been done successfully in 2+1 dimensions \cite{carlip3d}. Our
original goal was to provide a non-perturbative regularization of GR,
as a possible realization (and truly non-perturbative verification)
of the asymptotic safety scenario. For this reason we
have never added higher-order spatial
derivative terms to the bare action, as is done in HL gravity, but such terms
could in principle be created by the entropy factor. The phase diagram we
observe is quite similar to a Lifshitz diagram, indicating that
an interpretation in terms of HL gravity may be natural. An appealing possibility is
that our approach includes both scenarios, where the asymptotic
safety scenario with full GR invariance may correspond to a
special choice of bare coupling constants, i.e.\ a fine-tuning of
the relation between the Regge action and the entropy term in
the effective quantum action. Better data and more observables
will be required to discriminate between a ``pure gravity" behaviour and
an anisotropic deformation \`a la Ho\v rava-Lifshitz in the deep ultraviolet.

\subsection*{Acknowledgment}

JA and AG thank the Danish Research Council for financial
support via the grant "Quantum gravity and the role of black holes",
and the EU for support through the ERC Advanced
Grant 291092, "Exploring the Quantum Universe" (EQU).
JJ acknowledges partial support through the International
PhD Projects Programme of the Foundation
for Polish Science within the European Regional Development Fund of
the European Union, agreement no. MPD/2009/6.
RL acknowledges support through several
Projectruimte grants by the Dutch Foundation for Fundamental
Research on Matter (FOM). The contributions of JA and RL
were supported in part by the Perimeter Institute of Theoretical Physics.
Research at Perimeter Institute is supported by the Government of Canada
through Industry Canada and by the Province of Ontario through the
Ministry of Economic Development \& Innovation.

redpajama_set_name: RedPajamaArXiv


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This page was added on 29/03/2015.
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text:
By Alicia I. Kim
Photo by Mark Washburn
Hazard, left, observes an FRP patient.
As many as 50 million Americans suffer from chronic back pain, and only a small percentage of them can benefit from surgery. For the rest, the options for relief may be limited to standard physical therapy, painkillers, avoiding activities that aggravate their pain, or even changing jobs.
Specialized: But since 2003, Dr. Rowland Hazard and his colleagues at DHMC's Spine Center have been taking a different approach to back pain with the Functional Restoration Program (FRP). The 14-day program helps patients recover mobility, flexibility, strength, and endurance—despite their pain—with specialized physical training and education.
Rather than focusing just on pain relief, the FRP starts with understanding each patient's individual goals—such as returning to work, resuming a hobby, or simply doing household chores. The program includes dynamic workout sessions, as well as training in how to isolate and exercise key muscles whose function is essential for patients to meet their goals. There are also relaxation sessions to complement the physical activity. In addition, physicians teach patients pain-management strategies to help them maintain their newfound functionality.
Model: Patients in the FRP learn "what they can and can't do and what works for them, which is quite different from a top-down, authoritative model," explains Hazard. "Within that model of learning . . . people learn to trust themselves, and that's really a key to getting better. [Patients] leave here with a regimen . . . that they then continue on their own."
After completing the program, patients come back to the Spine Center one month and three months later for a follow-up assessment of their strength, flexibility, and endurance and of their pain, goals, and overall mood. Based on results from 300 recent graduates, the FRP works well; pain and depression scores go down and flexibility and strength scores go up. The program bases success on participants' satisfaction with their progress, rather than on a pathology-focused model based on meeting broad norms.
Idea: "It's very exciting," says Hazard, "to see people getting better with an approach that is not made up of pills and shots and surgeries." Hazard, who helped create the FRP, was inspired by a similar program at the University of Texas, where he did a fellowship in orthopaedics. He brought the concept to the Spine Center seven years ago and has been refining it ever since.
It's "exciting to see people getting better [without] pills and shots."
About 80 people participate in the FRP each year, coming from all over, primarily New England and New York State. They range from a soldier injured in Iraq to a teenager with inexplicable back pain. A great FRP candidate, says Hazard, is someone who can't work, have fun, or perform daily activities, even after trying medication, physical therapy, or surgery.
Patients bring varying attitudes and expectations, Hazard emphasizes. He and his colleagues recently assessed the effectiveness of using goal achievement to measure the success of the program. Their findings, based on one-year follow-up surveys and published in the journal Spine, showed that goal achievement was a better predictor of patients' satisfaction with the program than traditional measures, such as improvements in pain, flexibility, and endurance.
Disseminate: Hazard and his team are also working to disseminate what they have learned to other providers, nationally and locally. In the meantime, he looks forward to the arrival of each new crop of FRP patients, who arrive at the Spine Center with high hopes. "The program itself is 14 days," Hazard says, "but it's just the beginning."