Thermal fluctuations in non-equilibrium: From quantum to classical systems. Focus: Nonlinear systems

非线性系统，特别是远离平衡的系统，是统计物理学中一个令人兴奋的领域：无论是理论上还是实验上，平均值和波动的行为在很大程度上都是未知的。在这个项目中，我们的目标是在理论上描述这样的非线性系统的平衡，通过调查以下具体情况：i）的（量子）波动的电磁场在非线性系统，ii）布朗运动的驱动粒子在非线性浴，和iii）的非线性响应的胶体模型系统，其连接到波动的未扰动状态。

Nonlinear systems, especially if far from equilibrium, are an exciting field of statistical physics: The behavior of mean values as well as fluctuations are largely unexplored, both theoretically as well as experimentally. In this project, we aim at the theoretical description of such nonlinear systems out of equilibrium, by investigation of the following specific cases: i) The (quantum-) fluctuations of the electromagnetic field in nonlinear systems, ii) the Brownian motion of a driven particle in nonlinear bath, and iii) the nonlinear response of a colloidal model system, and its connection to fluctuations in the unperturbed state.