Diffusion in a partially absorbing medium with position and occupation time resetting
File(s)occupation_time.pdf (516.71 KB)
Accepted version
Author(s)
Bressloff, Paul C
Type
Journal Article
Abstract
In this paper we consider diffusion in a domain Ω containing a partially absorbing target $\mathcal{M}$ with position and occupation time resetting. The occupation time At is a Brownian functional that determines the amount of time that the particle spends in $\mathcal{M}$ over the time interval [0, t]. We assume that there exists some internal state ${\mathcal{U}}_{t}$ of the particle at time t which is modified whenever the particle is diffusing within $\mathcal{M}$. The state ${\mathcal{U}}_{t}$ is taken to be a monotonically increasing function of At, and absorption occurs as soon as ${\mathcal{U}}_{t}$ crosses some fixed threshold. We first show how to analyze threshold absorption in terms of the joint probability density or generalized propagator P(x, a, t|x0) for the pair (Xt, At) in the case of a non-absorbing substrate $\mathcal{M}$, where Xt is the particle position at time t and x0 is the initial position. We then introduce a generalized stochastic resetting protocol in which both the position Xt and the internal state ${\mathcal{U}}_{t}$ are reset to their initial values, Xt → x0 and ${\mathcal{U}}_{t}\to 0$, at a Poisson rate r. The latter is mathematically equivalent to resetting the occupation time, At → 0. Since resetting is governed by a renewal process, the survival probability with resetting can be expressed in terms of the survival probability without resetting, which means that the statistics of absorption can be determined by calculating the double Laplace transform of P(x, a, t|x0) with respect to t and a. In order to develop the basic theory, we focus on one-dimensional diffusion with $\mathcal{M}$ given by a finite or semi-infinite interval, and explore how the mean first passage time with resetting depends on various model parameters. We also compare the threshold mechanism with the classical case of a constant absorption rate.
Date Issued
2022-06-01
Date Acceptance
2022-06-04
Citation
Journal of Statistical Mechanics: Theory and Experiment, 2022, 2022 (6)
ISSN
1742-5468
Publisher
IOP Publishing
Journal / Book Title
Journal of Statistical Mechanics: Theory and Experiment
Volume
2022
Issue
6
Copyright Statement
Copyright © 2022 IOP Publishing Ltd. This is an author-created, un-copyedited version of an article published in Journal of Statistical Mechanics: Theory and Experiment. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/1742-5468/ac7796
Identifier
http://dx.doi.org/10.1088/1742-5468/ac7796
Publication Status
Published
Article Number
063207
Date Publish Online
2022-06-30