Speaker
Shin Nakamura
(Chuo University)
Description
The fluctuation–response inequality (FRI), proposed by Dechant and Sasa, is a general relation between fluctuations and responses in nonequilibrium systems. For instance, the FRI states that the ratio of the effective temperature to the differential mobility of a test particle in a thermal bath is a non-decreasing function of the particle’s velocity. In this work, we compute both the effective temperature and the differential mobility of a probe in a thermal bath using gauge/gravity duality in various gravitational backgrounds. We find that the FRI is satisfied in most setups consistent with superstring theory, with the exception of a few ill-defined cases. We also discuss how the geometry on the gravity side is constrained by the FRI.