arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.06989cond-mat.stat-mech
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任意维自由落体粒子的万有性质

Universal Properties of a Run-and-Tumble Particle in Arbitrary Dimension

Francesco Mori, Pierre Le Doussal, Satya N. Majumdar, Gregory Schehr

摘要:

我们考虑一个活跃的运行和翻滚粒子(RTP)在$d$尺寸,从原点开始,并在一个时间间隔$[0,t]$的演变。我们研究了三种不同的模型的RTP的动态:标准RTP模型与瞬时tumerance,一个变种与瞬时运行和一个一般的模型,其中的tumerance和运行是非瞬时的。对于这些模型中的每一个,我们使用离散时间随机游动的Sparre Andersen定理来精确计算$x$分量不改变时间$t$的符号的概率,表明它不依赖于$d$。由于这一结果,我们精确计算其他$x$组件的属性,即最大值和记录统计的时间分布,表明它们是通用的,即它们不依赖于$d$。此外,我们表明,这些普遍的结果也持有,如果速度$v$的粒子后,每次翻滚是随机的,从一个通用的概率分布。我们的研究结果得到了数值模拟的证实。其中一些结果已在最近的一封信中宣布[物理学。124,090603(2020)]。

英文摘要:

We consider an active run-and-tumble particle (RTP) in $d$ dimensions, starting from the origin and evolving over a time interval $[0,t]$. We examine three different models for the dynamics of the RTP: the standard RTP model with instantaneous tumblings, a variant with instantaneous runs and a general model in which both the tumblings and the runs are non-instantaneous. For each of these models, we use the Sparre Andersen theorem for discrete-time random walks to compute exactly the probability that the $x$ component does not change sign up to time $t$, showing that it does not depend on $d$. As a consequence of this result, we compute exactly other $x$-component properties, namely the distribution of the time of the maximum and the record statistics, showing that they are universal, i.e. they do not depend on $d$. Moreover, we show that these universal results hold also if the speed $v$ of the particle after each tumbling is random, drawn from a generic probability distribution. Our findings are confirmed by numerical simulations. Some of these results have been announced in a recent Letter [Phys. Rev. Lett. 124, 090603 (2020)].

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。

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