Vacuum Structure and Boundary Renormalization Group

TL;DR

This paper investigates how boundary conditions influence vacuum properties and thermodynamic quantities in 2D conformal field theories, revealing boundary entropy's sensitivity and entanglement entropy's independence under certain conditions.

Contribution

It provides a detailed analysis of the behavior of vacuum energy, boundary entropy, and entanglement entropy under boundary renormalization group flow in 2D CFTs, highlighting their different sensitivities.

Findings

Vacuum energy and boundary entropy are sensitive to boundary conditions.

Vacuum entanglement entropy is unaffected when the entanglement boundary does not overlap the physical boundary.

The second law of thermodynamics is upheld along the boundary RG flow.

Abstract

The vacuum structure is probed by boundary conditions. The behaviour of thermodynamical quantities like free energy, boundary entropy and entanglement entropy under the boundary renormalization group flow are analysed in 2D conformal field theories. The results show that whereas vacuum energy and boundary entropy turn out to be very sensitive to boundary conditions, the vacuum entanglement entropy is independent of boundary properties when the boundary of the entanglement domain does not overlap the boundary of the physical space. In all cases the second law of thermodynamics holds along the boundary renormalization group flow.