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math.PR2026

Penalizations of Two-Dimensional Simple Random Walk by Direction-Dependent Excursion Counts and Edge-Crossing Counts

Syota Esaki, Kohki Iba

We study penalizations of the two-dimensional simple random walk by functions of direction-dependent excursion counts and edge-crossing counts. The former record completed excursio…

math.PR2026

Fredholm and Sturm--Liouville Type Characterizations of the Limit Measure for the Kac Killing Penalization for Lévy Processes

Kohki Iba

We study the Kac killing penalization for a one-dimensional recurrent Lévy process. We prove that the limit process possesses two equivalent characterizations by a Fredholm equatio…

math.PR2026

Elephant Random Walk Conditioned to Avoid Zero

Kohki Iba, Go Tokumitsu

We investigate the long-time limit of an elephant random walk conditioned to avoid zero and show that the resulting process admits a Skorokhod-type embedding into a three-dimension…

math.PR2026

A Tanaka-Type Formula for Compact Sets and Equilibrium Measures of Lévy Processes

Kohki Iba, Victor Rivero

Tanaka's formula is a classical identity for Brownian motion, and Tsukada (2018) extended it to Lévy processes not necessarily symmetric. From a potential-theoretic point of view,…

math.PR2026

Hitting Probabilities of Finite Points for One-Dimensional Lévy Processes

Kohki Iba

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…