content_image/299417.jpg content_image/299418.jpg content_image/299419.jpg
problem into a modern string theoretic version of the 1696 Brachistochrone problem and yields a remarkable, simple analytic solution for the string shape and momentum loss per unit time. 

## 5.2 AdS/CFT compared to pQCD 

Exploiting the AdS/CFT correspondence, the drag coefficient for a massive quark moving through a strongly-coupled SYM plasma in the λ = g 2 $_{SY M}$N$_{c}$ ≫ 1, N$_{c}$ ≫ 1, M$_{Q}$ ≫ T ∗ limit is given in [342, 343, 347] as 

<img src='content_image/299417.jpg'>

where T ∗ is the temperature of the SYM plasma as fixed by the Hawking temperature of the dual D3 black brane. This is parametrically quite similar to the Bethe-Heitler limit of incoherent radiative energy loss, in which case 

<img src='content_image/299418.jpg'>

differing from Eq. (5.1) only by a factor of T/M , and quite dissimilar to the usual LPM-dominated asymptotic pQCD result, 

<img src='content_image/299419.jpg'>

There exists a maximum momentum, or γ$_{c}$ ≈ p crit T /M$_{Q}$ beyond which Eq. 

