Probability Seminar

Christopher JanjigianPurdue University
Infinite geodesics and Busemann functions in inhomogeneous exponential last passage percolation

Monday, September 9, 2024 - 4:00pm
Malott 406

This talk will discuss some recent progress on understanding the structure of semi-infinite geodesics and their associated Busemann functions in the inhomogeneous exactly solvable exponential last-passage percolation model. In contrast to the homogeneous model, this generalization admits linear segments of the limit shape and an associated richer structure of semi-infinite geodesic behaviors. Depending on certain choices of the inhomogeneity parameters, we show that the model exhibits new behaviors of semi-infinite geodesics, which include wandering semi-infinite geodesics with no asymptotic direction, isolated asymptotic directions of semi-infinite geodesics, and non-trivial intervals of directions with no semi-infinite geodesics. Based on joint work with Elnur Emrah (Bristol) and Timo Seppäläinen (Madison)