标题： 运动调节活性物质中的接触力 显示英文标题

标题： Contact Forces in Motility-Regulated Active Matter

摘要： 长程相互作用在自然界中无处不在，它们在细胞尺度上通过扩散场介导，或通过视觉线索介导动物群体之间的相互作用。短程力在物理学中是典型的，因此在建模由介导相互作用引起的生物系统的集体行为时，通常可以忽略。然而，当自组织导致致密相的出现时，我们表明排除体积相互作用起着重要而多样的作用。我们考虑由于运动调节而发生凝聚或相分离的活性粒子集合，并表明短程排斥力可以产生相反的效果。当运动调节触发吸收相变，如趋化性坍缩时，排斥力会阻碍凝结物的形成并稳定有限密度相的共存。相反，当运动调节引起液气共存时，排斥力反而可能导致液相密度显著增加。 显示英文摘要

摘要： Long-range interactions are ubiquitous in nature, where they are mediated by diffusive fields at the cellular scale or by visual cues for groups of animals. Short-range forces, which are paradigmatic in physics, can thus often be neglected when modeling the collective behaviors of biological systems induced by mediated interactions. However, when self-organization leads to the emergence of dense phases, we show that excluded-volume interactions play an important and versatile role. We consider assemblies of active particles that undergo either condensation or phase-separation due to motility regulation and show that short-range repulsive forces can induce opposite effects. When motility regulation triggers an absorbing phase transition, such as a chemotactic collapse, repulsive forces opposes the formation of condensates and stabilize the coexistence between finite-density phases. In contrast, when motility regulation induces liquid-gas coexistence, repulsive forces can, counterintuitively, lead to a significant increase in the liquid density.