# What is the experimental status of AdS/CFT, AdS/QCD, AdS/CMT, etc?

What experiments have challenged or supported AdS/QCD, AdS/CMT, etc? What experiments should we look forward to do this?

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This is not my comment but an anonymously suggested and rejected edit to John Rennie's answer: Any application of AdS/CFT to a practical system in 3 space dimensions would require that the system is goverend by a quantum gauge field theory in (3+1) dimensions that has the following three properties: 1. Maximal supersymmetry. 2. Conformal invariance 3. Large number of colors Since no such system has been found so far to exist in nature, one must assume some reasonable approximations in applying AdS/CFT to a system. Quark gluon plasma being produced by LHC fits this criterion. – Dilaton Feb 23 '13 at 23:52

According to the Backreaction blog there is evidence from heavy ion collisions that contradicts Ads/CFT. However even is this is true (I have no way of judging) all it contradicts is the application of Ads/CFT to heavy ion collisions, and everyone knows it could at best be an approximation because heavy ion collisions aren't supersymmetric.

At the risk of stepping beyond my (meagre) knowledge of the area, at the moment there can't be any experimental tests because the CFT bit of Ads/CFT has to be supersymmetric and there are no know supersymmetric physical systems.

An important result of AdS/CFT is the calculation of a lower bound for the ratio of viscosity and entropy density of a relativistic fluid, $\frac{\eta}{s}=\frac{1}{4\pi}\frac{\hbar}{k_B}.$ This is consistent with the outcome of experiments at the RHIC, in which the role of the fluid is played by the quark gluon plasma.