Extracting more information from entropy

Abstract

We extract the complex frequency of the lowest quasinormal mode (QNM) from the holographically computed entropy density near thermodynamic equilibrium. The system under study is a purely thermal supersymmetric Yang-Mills N=4 plasma undergoing homogeneous isotropization dynamics. Starting from a far-from-equilibrium initial state, the system evolves toward equilibrium entropy, forming a stairway pattern. Our analysis reveals that the rate of increase of the stairway is twice the decay rate (imaginary part) of the lowest QNM. Based on this observation, we propose a model that explains how this information is encoded in the entropy. The model is further extended to include finite temperature, R-charge density, and scalar condensate, revealing an additional feature: the system’s dominant dissipation channel may shift to one driven by the scalar condensate, depending on the chemical potential. Published by the American Physical Society 2025