2025/06/16 by Huang, Feng, Chen, Hanshuang · 1 citation
#FOS: Physical sciences #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2506.13112
We investigate the first-passage properties and extreme-value statistics of an overdamped Brownian particle confined by an external linear potential V(x)=μ|x-x0|, where μ>0 is the strength of the potential and x0>0 is the position of the lowest point of the potential, which coincides with the starting position of the particle. The Brownian motion terminates whenever the particle passes through the origin at a random time tf. Our study reveals that the mean first-passage time ⟨ tf ⟩ exhibits a nonmonotonic behavior with respect to μ, with a unique minimum occurring at an optimal value of μ≃ 1.24468D/x0, where D is the diffusion constant of the Brownian particle. Moreover, we examine the distribution P(M|x0) of the maximum displacement M during the first-passage process, as well as the statistics of the time tm at which M is reached. Intriguingly, there exists another optimal μ≃ 1.24011 D/x0 that minimizes the mean time ⟨ tm ⟩. All our analytical findings are corroborated through numerical simulations.