Hitting Probabilities of Finite Points for One-Dimensional Lévy Processes
Kohki Iba
TL;DR
This work derives explicit formulas for the probability that a one-dimensional Lévy process starting at $x$ first hits a specified point among a finite set $A_n$, expressing these hitting probabilities solely through the renormalized zero resolvent $h$. It extends classic two-point hitting results to multi-point configurations and connects them to the $Q$-matrix of the trace process on $A_n$, under recurrent and transient regimes. The approach combines excursion theory, local time, and resolvent analysis, yielding concrete representations for Brownian motion, stable processes, and spectrally negative Lévy processes. The results provide practical tools for computing hitting probabilities and trace-process dynamics in one dimension, with explicit illustrations in Section 5.
Abstract
For a one-dimensional Lévy process, we derive an explicit formula for the probability of first hitting a specified point among a fixed finite set. Moreover, using this formula, we obtain an explicit expression for each entry of the $Q$-matrix of the trace process on the finite set. These formulas involve solely the renormalized zero resolvent.
