Alladi Ramakrishnan Hall

Zero temperature dissipation and holography

Pinaki Banerjee

IMSc

We use holographic techniques to study the zero-temperature limit of dissipation for a Brownian particle moving in a strongly coupled CFT at finite temperature in various space-time dimensions. The dissipative term in the boundary theory in certain limit (for ω → 0, T → 0 with ω/T held small and fixed) does not match the same at T = 0, ω → 0. Thus the T → 0 limit is not smooth for ω < T. This phenomenon appears to be related to a confinement- deconfinement phase transition at T = 0 in the field theory.

We also study Brownian motion at zero and small (but
finite) temperature in presence of finite density by studying the dynamics of a fundamental string in an (near-) extremal RN black hole. We compute analytically the functional form of retarded Green’s function and also compare that numerically at leading order in small frequency.