论文标题
通过线性限制电势与随机返回重置
Resetting with stochastic return through linear confining potential
论文作者
论文摘要
我们认为,在一个维度上重置的过度引导的棕色粒子的运动。与通常的设置相反,粒子即时重置为首选位置(例如原点),在这里我们考虑了由外部线性势$ V(x)=λ| x |〜(λ> 0)$的有限时间重置过程。重置时,陷阱会打开,粒子会经历力$ - \ partial_x v(x)$,这有助于粒子返回重置位置。粒子首次通向原点后,陷阱立即关闭。随后,粒子恢复其自由扩散运动,过程不断重复。在此设置中,系统达到了非平衡稳态。我们通过分析始终计算粒子的位置分布,然后使用相应的Fokker-Planck操作员的光谱特性来分析该分布,从而研究了这种稳态的松弛。如瞬时重置问题所见,我们观察到一个“圆锥体扩散”的放松在行进前线,使得重置点周围有一个内部核心区域达到稳定状态,而核心外部的区域仍会随着时间的推移而弹道。除了异常的弛豫现象外,我们还计算了与相应概率密度相关的大偏差函数,并发现大偏差函数描述了与瞬时重置相似的动力转变。值得注意的是,我们的方法基于光谱特性,可以补充现有的续签形式主义,并揭示了负责这种放松现象的复杂数学结构。我们针对广泛的数值模拟验证了我们的分析结果。
We consider motion of an overdamped Brownian particle subject to stochastic resetting in one dimension. In contrast to the usual setting where the particle is instantaneously reset to a preferred location (say, the origin), here we consider a finite time resetting process facilitated by an external linear potential $V(x)=λ|x|~ (λ>0)$. When resetting occurs, the trap is switched on and the particle experiences a force $-\partial_x V(x)$ which helps the particle to return to the resetting location. The trap is switched off as soon as the particle makes a first passage to the origin. Subsequently, the particle resumes its free diffusion motion and the process keeps repeating. In this set-up, the system attains a non-equilibrium steady state. We study the relaxation to this steady state by analytically computing the position distribution of the particle at all time and then analysing this distribution using the spectral properties of the corresponding Fokker-Planck operator. As seen for the instantaneous resetting problem, we observe a `cone spreading' relaxation with travelling fronts such that there is an inner core region around the resetting point that reaches the steady state, while the region outside the core still grows ballistically with time. In addition to the unusual relaxation phenomena, we compute the large deviation functions associated to the corresponding probability density and find that the large deviation functions describe a dynamical transition similar to what is seen previously in case of instantaneous resetting. Notably, our method, based on spectral properties, complements the existing renewal formalism and reveals the intricate mathematical structure responsible for such relaxation phenomena. We verify our analytical results against extensive numerical simulations.