Expectation values of boundary fields in the boundary sine-Gordon model

TL;DR

This paper derives an explicit formula for the vacuum expectation values of boundary fields in the boundary sine-Gordon model with zero bulk mass, aligning with known results and perturbative calculations.

Contribution

It provides a new explicit expression for boundary field expectation values in the boundary sine-Gordon model, confirming consistency with existing results.

Findings

Expression agrees with boundary free energy results

Matches perturbative calculations

Valid for zero bulk mass case

Abstract

We propose an explicit expression for vacuum expectation values of the boundary field e^{ia\phi_{B}} in the boundary sine-Gordon model with zero bulk mass. This expression agrees with known exact results for the boundary free energy and with perturbative calculations.