Theoretische Physik I, Universität Bayreuth, 95440 Bayreuth, Germany.
Phys Rev E. 2018 Aug;98(2-1):020603. doi: 10.1103/PhysRevE.98.020603.
We identify active phase separation as a generic demixing phenomenon in nonequilibrium systems with conservation constraints. Examples range from cell polarization to cell populations communicating via chemotaxis, and from self-propelled particle communities to mussels in ecology. We show that system-spanning properties of active phase separation in nonequilibrium systems near onset are described by the classical Cahn-Hilliard (CH) model. This result is rather surprising since the CH equation is famous as a model for phase separation at thermal equilibrium. We introduce a general reduction scheme to establish a unique mathematical link between the generic CH equation and system-specific models for active phase separation. This approach is exemplarily applied to a model for polarization of cells and a model for chemotactic cell communities. For cell polarization, we also estimate the validity range of the CH model.
我们将活跃的相分离识别为具有守恒约束的非平衡系统中的一种通用混合现象。其例子包括从细胞极化到通过趋化性进行通信的细胞群体，以及从自推进粒子群落到生态学中的贻贝。我们表明，在非平衡系统中，活跃的相分离在接近开始时的系统跨度性质由经典的 Cahn-Hilliard（CH）模型描述。这一结果相当令人惊讶，因为 CH 方程以热平衡时相分离的模型而闻名。我们引入了一种通用的简化方案，在通用 CH 方程和用于活跃相分离的特定于系统的模型之间建立了唯一的数学联系。这种方法被专门应用于细胞极化模型和趋化性细胞群落模型。对于细胞极化，我们还估计了 CH 模型的有效范围。
