QLunch: Frederik Ravn Klausen

Speaker: Frederik Ravn Klausen from QMATH

Title: Critical exponents for the Ising model in a magnetic field with random currents

Abstract: We discuss exponential decay of truncated correlation functions for the two dimensional Ising model in a uniform magnetic field at the critical temperature. The critical exponent corresponding to the scaling of the correlation length in the limit of small fields has been known to be 8/15 for almost 50 years by physicists. Recently, the result was rigorously proven by Camia-Jiang-Newmann using connections to the conformal loop ensemble. We will discuss this as well as another low-tech proof using graphical representations for the Ising model. The intriguing connections to experiments, perturbed conformal field theory and the exceptional Lie Algebra E_8 will be mentioned.