mapping theoretical input parameters back to usable information on plasma properties. Recent work by Phenix has attempted to rigorously statistically quantify the knowledge of the controlling model input parameters to be gained from data [310, 311]. For WHDG the result is dN$_{g}$/dy = 1400 +200 − 375 and +600 − 540 at the 68% and the 95% confidence levels, respectively. While the 1-sigma constraint is within ∼ 20%, the parameter range consistent with data at the 2-sigma level varies by a factor of 2; this turns out to be roughly true for all the energy loss models. 

Regrettably this calculation was not able to take into account any theo- retical error, which has not been extensively researched by any group. Recent estimates of the error solely due to the running coupling are not promising; see Fig. 2.10. And there is the large systematic error of vastly different ap- proximations going into the modeling. This suggests three courses of research for theoretical high- p$_{T}$ physics: (1) search for observables that are more theo- retically sensitive, (2) more rigorous estimates of major sources of theoretical error and the possibility of minimizing them, or (3) search for qualitative tests of theoretical formalisms and approximations. We pursue the latter option in this thesis. 

## 2.3 Introduction to AdS/CFT 

The AdS/CFT conjecture is possibly the most important new theoretical tool developed in the past two decades. It claims a correspondence, or duality, 

