Nondiffusive Fluxes in Brownian System with Lorentz Force

Stationary and transient Fluctuation Theorems for effective heat flux between hydrodynamically coupled particles in optical traps

We experimentally study the statistical properties of the energy fluxes between two trapped Brownian particles, interacting through dissipative hydrodynamic coupling, submitted to an effective temperature difference $ΔT$, obtained by random forcing the position of one trap. We identify effective heat fluxes between the two particles and show that they satisfy an exchange fluctuation theorem (xFT) in the stationary state. We also show that after the sudden application of a temperature gradient $ΔT$, \resub{the total} hot-cold flux satisfies \resub{a} transient xFT for any integration time where…

Brownian Molecules Formed by Delayed Harmonic Interactions

A time-delayed response of individual living organisms to information exchanged within flocks or swarms leads to the emergence of complex collective behaviors. A recent experimental setup by (Khadka et al 2018 Nat. Commun. 9 3864), employing synthetic microswimmers, allows to emulate and study such behavior in a controlled way, in the lab. Motivated by these experiments, we study a system of N Brownian particles interacting via a retarded harmonic interaction. For $N \leq 3$ , we characterize its collective behavior analytically, by solving the pertinent stochastic delay-differential equations…

On the Depletion Effect in Colloids: Correlated Brownian Motions

Our object is to formulate and analyze a physically plausible and mathematically sound model to better understand the phenomenon of clumping in colloid dispersions. Our model is stochastic but rigorously derived from a deterministic setup in a Newtonian setting. A rigorous transition from deterministic mean-field dynamics of several large particles and infinitely many small particles to the stochastic motion of the large particles is invoked. Then the stochastic motion of the large particles is described by a system of correlated Brownian motions. The scaling in the transition preserves a char…

Heat, temperature and Clausius inequality in a model for active brownian particles

Methods of stochastic thermodynamics and hydrodynamics are applied to the a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from the system's Fokker-Planck equation the average exchanges of heat and work with the active bath and the associated entropy production. We show that a Clausius inequality holds, with the local (non-uniform) temperature of the active bath replacing the uniform temperature usually encountered in equilibrium systems. Furthermore, by restricting…

手性活性环境中可调组装力的微观起源

Microscopic origin of tunable assembly forces in chiral active environments

本文研究了活性浴中被动溶质间相互作用的微观起源，发现非手性活性浴无法动态引发组装，而手性活性粒子能产生稳定的长程组装力，其机制与奇扩散张量通量相关。

利用流匹配捕捉非平衡随机系统中的非马尔可夫动力学

Capturing non-Markovian dynamics in non-equilibrium stochastic systems using flow matching

针对粗粒化随机偏微分方程无法准确捕捉短时非马尔可夫效应和低密度非高斯分布的问题，提出生成式流匹配方法直接建模粒子模拟中的概率通量分布，在Kramers首通时间问题中准确捕捉短时行为并改进数密度统计矩预测。

Transport coefficients for driven granular mixtures at low-density

The transport coefficients of a granular binary mixture driven by a stochastic bath with friction are determined from the inelastic Boltzmann kinetic equation. A normal solution is obtained via the Chapman-Enskog method for states near homogeneous steady states. The mass, momentum, and heat fluxes are determined to first order in the spatial gradients of the hydrodynamic fields, and the associated transport coefficients are identified. They are given in terms of the solutions of a set of coupled linear integral equations. As in the monocomponent case, since the collisional cooling cannot be co…