Sep 30, 2021
A new approach to the Berezinskii–Kosterlitz–Thouless transition in the planar XY model
VIENNA PROBABILITY SEMINAR
Date: September 30, 2021 |
2:00 pm –
Speaker: Marcin Lis, Uni Wien
Location: Rényi Institute Budapest
We present a new proof of the BKT phase transition in the spin XY (planar rotor) model on any planar lattice — a result first established by Fröhlich and Spencer in 1981. Our approach is quite elementary. It does not go through the analysis of vortices but rather through the dual integer-valued height function. We use a recent result of Lammers on delcoalization of general height functions together with a new loop representation of spin correlations in the XY model, that we believe to be of independent interest. This is joint work with Diederik van Engelenburg.