Goswami Koushik, Chakrabarti Rajarshi
Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, Powai 400076, India.
Phys Rev E. 2021 Sep;104(3-1):034113. doi: 10.1103/PhysRevE.104.034113.
We study the dynamics of an overdamped Brownian particle subjected to Poissonian stochastic resetting in a nonthermal bath, characterized by a Poisson white noise and a Gaussian noise. Applying the renewal theory we find an exact analytical expression for the spatial distribution at the steady state. Unlike the single exponential distribution as observed in the case of a purely thermal bath, the distribution is double exponential. Relaxation of the transient spatial distributions to the stationary one, for the limiting cases of Poissonian rate, is investigated carefully. In addition, we study the first-arrival properties of the system in the presence of a delta-function sink with strength κ, where κ=0 and κ=∞ correspond to fully nonreactive and fully reactive sinks, respectively. We explore the effect of two competitive mechanisms: the diffusive spread in the presence of two noises and the increase in probability density around the initial position due to stochastic resetting. We show that there exists an optimal resetting rate, which minimizes the mean first-arrival time (MFAT) to the sink for a given value of the sink strength. We also explore the effect of the strength of the Poissonian noise on MFAT, in addition to sink strength. Our formalism generalizes the diffusion-limited reaction under resetting in a nonequilibrium bath and provides an efficient search strategy for a reactant to find a target site, relevant in a range of biophysical processes.
我们研究了在非热浴中受到泊松随机重置的过阻尼布朗粒子的动力学,该非热浴由泊松白噪声和高斯噪声表征。应用更新理论,我们得到了稳态下空间分布的精确解析表达式。与纯热浴情况下观察到的单指数分布不同,该分布是双指数的。我们仔细研究了泊松率极限情况下瞬态空间分布向稳态分布的弛豫。此外,我们研究了在强度为κ的δ函数汇存在时系统的首次到达性质,其中κ = 0和κ = ∞分别对应于完全无反应和完全反应的汇。我们探讨了两种竞争机制的影响:在两种噪声存在下的扩散传播以及由于随机重置导致初始位置周围概率密度的增加。我们表明,对于给定的汇强度值,存在一个最优重置率,它使到达汇的平均首次到达时间(MFAT)最小化。除了汇强度外,我们还探讨了泊松噪声强度对MFAT的影响。我们的形式主义推广了非平衡浴中重置下的扩散限制反应,并为反应物找到目标位点提供了一种有效的搜索策略,这在一系列生物物理过程中具有相关性。