The Ubiquitous 'c': from the Stefan-Boltzmann Law to Quantum Information

TL;DR

This paper explores the significance of the conformal anomaly number c in 2D and 1+1D critical phenomena, highlighting its roles from thermodynamics to quantum entanglement and classification of universality classes.

Contribution

It provides a comprehensive discussion of the multifaceted importance of the conformal anomaly number c across various aspects of conformal field theory and critical phenomena.

Findings

c acts as an analogue of Stefan's constant in 2D systems

c is fundamental in classifying 2D universality classes

c measures quantum entanglement in critical systems

Abstract

I discuss various aspects of the role of the conformal anomaly number c in 2- and 1+1-dimensional critical behaviour: its appearance as the analogue of Stefan's constant, its fundamental role in conformal field theory, in the classification of 2d universality classes, and as a measure of quantum entanglement, among other topics.