Level spectroscopy II - application to the Gaussian model -

TL;DR

This paper presents a new method based on renormalization group analysis to accurately determine the Gaussian fixed line in models where correlation length divergence is slow near multicritical points.

Contribution

It introduces an efficient approach for identifying the Gaussian fixed line from numerical data, addressing challenges near the BKT multicritical point.

Findings

The method effectively locates the Gaussian fixed line in the Gaussian model.

It overcomes difficulties caused by slow divergence of correlation length.

The approach enhances understanding of critical behavior in complex systems.

Abstract

It was a difficult problem to determine the Gaussian fixed line from the numerical data, because close to the Berezinskii-Kosterlitz-Thouless multicritical point the divergence of the correlation length becomes very slow. Considering the renormalization group behavior, we find an efficient method to determine the Gaussian fixed line.