Ayla Stam

collaborators

2 papers

math.CO2023

A near-optimal zero-free disk for the Ising model

Viresh Patel, Guus Regts, Ayla Stam

The partition function of the Ising model of a graph $G = (V, E)$ is defined as $Z_{Ising} (G; b) = \sum_{σ : V \to {0, 1}} b^{m (σ)}$ , where $m (σ)$ denotes the number of edges $e=\{u…

math.CO2021

Improved bounds for zeros of the chromatic polynomial on bounded degree graphs

Maurizio Moreschi, Viresh Patel, Guus Regts +1

We prove that for any graph $G$ of maximum degree at most $Δ$ , the zeros of its chromatic polynomial $χ_{G} (z)$ (in $C$ ) lie outside the disk of radius $5.02Δ$ centered at…