2024/09/27 by Tian, Lulu, Chen, Hanshuang, Li, Guofeng
#FOS: Physical sciences #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2409.18398
We consider high-order stochastic processes x(t) described by the Langevin equation \fracdmx( t )dtm= √(2D) ξ(t), where ξ(t) is a delta-correlated Gaussian noise with zero mean, and D is the strength of noise. We focus on the short-time statistics of the first-passage functionals A=∫0T [ x(t)] n dt along the trajectories starting from x(0)=L and terminating whenever passing through the origin for the first-time at t=T. Using the optimal fluctuation method, we analytically obtain the most likely realizations of the first-passage processes for a given constraint A with n=0 and 1, corresponding to the first-passage time itself and the area swept by the first-passage trajectory, respectively. The tail of the distribution of A shows an essential singularity at A → 0, Pm,n(A |L) ∼ exp(-\fracαm,nL2mn-n+2D A2m-1 ), where the explicit expressions for the exponents αm,0 and αm,1 for arbitrary m are obtained.