Probability Seminar - Andrew Heeszel

andy-heeszel
Thu, February 19, 2026
10:20 am - 11:15 am
Math Tower (MW) 154

Andrew Heeszel
The Ohio State University

Title
Limiting speed and fluctuations for the boundary modified contact process

Abstract
In this talk we show a law of large numbers and central limit theorem for the edge speeds of the model (BMCP). The BMCP models an epidemic spreading across the integer lattice $\mathbb{Z}$ with two infection parameters $\lambda_i$ and $\lambda_e$. Starting from a finite infected set, each edge of $\mathbb{Z}$ transmits the infection at rate $\lambda_i$ except for the rightmost and leftmost edges incident to infected vertices, which transmit the infection at rate $\lambda_e$. We study the model when the interior infection rate is at the critical infection rate of the contact process and cannot sustain the infection, while the exterior infection rate $\lambda_e > \lambda_c$. Adding a boost to the exterior infection rates causes the BMCP to no longer be an attractive particle system, requiring new tools in its study. We also show the likelihood of the infection dying out after a long but finite time scales at the stretched exponential rate, in contrast with the supercritical contact process.