# Stationary half-space last passage percolation

## TL;DR

This paper investigates the limiting distribution of last passage times in stationary half-space percolation, revealing a new two-parameter family of distributions that generalize known results and connect to Baik--Rains distributions.

## Contribution

It introduces a novel two-parameter family of distributions for stationary half-space last passage percolation, extending the understanding of such models beyond the full-space case.

## Key findings

- Derived the limiting distribution near the origin in a critical window.
- Showed convergence of the new distributions to Baik--Rains distributions away from the characteristic line.
- Utilized integrable models with Pfaffian structure and steepest descent analysis.

## Abstract

In this paper we study stationary last passage percolation (LPP) in half-space geometry. We determine the limiting distribution of the last passage time in a critical window close to the origin. The result is a new two-parameter family of distributions: one parameter for the strength of the diagonal bounding the half-space (strength of the source at the origin in the equivalent TASEP language) and the other for the distance of the point of observation from the origin. It should be compared with the one-parameter family giving the Baik--Rains distributions for full-space geometry. We finally show that far enough away from the characteristic line, our distributions indeed converge to the Baik--Rains family. We derive our results using a related integrable model having Pfaffian structure together with careful analytic continuation and steepest descent analysis.