对局部扰动的集体响应：如何在不丧失连贯性的情况下规避威胁
Collective response to local perturbations: how to evade threats without losing coherence
AI总结：
研究生命群体在局部扰动下的全局转向响应机制，利用自推进粒子最小模型揭示集体转向时间随系统规模增长的有限尺寸效应，并指出高效信息传播和适度运动性是维持群体连贯转向的必要条件。
摘要：
生命群体在复杂环境中移动，不断受到外部刺激、捕食者攻击和干扰的侵扰。对这类扰动的高效响应对于维持群体的连贯性和凝聚力至关重要。扰动通常是局部的，即最初仅被群体中的少数个体感知，却能引发全局响应。椋鸟群就是如此，它们能够非常迅速地转向以躲避捕食者。本文研究了在局部扰动下发生全局方向改变的条件。使用自推进粒子的最小模型，我们表明集体方向响应发生在随系统规模增长的时间尺度上，因此是一种有限尺寸效应。群体越大，转向所需的时间就越长。我们还表明，只有在以下情况下才能发生全局连贯转向：i）信息传播机制足够高效，能够将局部反应无衰减地传递到整个群体；以及 ii）运动性不能太强，以避免受扰动的个体在转向完成前离开群体。若不满足这些条件，将导致群体分裂或响应效率低下。
英文摘要：
Living groups move in complex environments and are constantly subject to external stimuli, predatory attacks and disturbances. An efficient response to such perturbations is vital to maintain the group's coherence and cohesion. Perturbations are often local, i.e. they are initially perceived only by few individuals in the group, but can elicit a global response. This is the case of starling flocks, that can turn very quickly to evade predators. In this paper, we investigate the conditions under which a global change of direction can occur upon local perturbations. Using minimal models of self-propelled particles, we show that a collective directional response occurs on timescales that grow with the system size and it is, therefore, a finite-size effect. The larger the group is, the longer it will take to turn. We also show that global coherent turns can only take place if i) the mechanism for information propagation is efficient enough to transmit the local reaction undamped through the whole group; and if ii) motility is not too strong, to avoid that the perturbed individual leaves the group before the turn is complete. No compliance with such conditions results in the group's fragmentation or in a non-efficient response.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
