On Wednesday, May 24th, at 14h00 in Aula 2001 (change of usual place! Aula 2001 is on the top floor of the Math Department, close to the copy shop) at Roma Tor Vergata, RoMaDS (https://www.mat.uniroma2.it/~rds/about.php) will host Rongfeng Sun (NUS Singapore) with the seminar

“A new correlation inequality for Ising models with external fields"

Abstract:

We study ferromagnetic Ising models on finite graphs with an inhomogeneous external field. We show that the influence of boundary conditions on any given spin is maximised when the external field is identically 0. One corollary is that spin-spin correlation is maximised when the external field vanishes. In particular, the random field Ising model on Z^d, d ≥ 3, exhibits exponential decay of correlations in the entire high temperature regime of the pure Ising model. Another corollary is that the pure Ising model on Z^d, d ≥ 3, satisfies the conjectured strong spatial mixing property in the entire high temperature regime. Based on joint work with Jian Ding and Jian Song.

We encourage in-person partecipation. Should you be unable to come, here is the link to the Teams streaming: https://teams.microsoft.com/l/meetup-join/19%3arfsL73KX-fw86y1YnXq2nk5VnZFwPU-iIPEmqet8NCg1%40thread.tacv2/1684401989008?context=%7b%22Tid%22%3a%2224c5be2a-d764-40c5-9975-82d08ae47d0e%22%2c%22Oid%22%3a%22f8a47851-5861-456e-8a18-d821f2c32894%22%7d .

The seminar is part of the Excellence Project MatMod@TOV.