Irrelevant Deformations with Boundaries and Defects

TL;DR

This paper explores the effects of $T\bar T$-like irrelevant deformations on quantum field theories with boundaries and defects, deriving deformed scattering matrices and spectral data.

Contribution

It introduces a formalism for analyzing $T\bar T$-like deformations in boundary and defect quantum field theories, including deformed scattering matrices and spectral flow equations.

Findings

Derived deformed bulk and boundary/defect scattering matrices.

Established flow equations for finite volume spectrum.

Computed the deformed cylinder partition function and $g$-function.

Abstract

We initiate the study of $T\bar T$-like irrelevant solvable deformations in quantum field theory with boundaries and defects. For this purpose, we employ a general formalism developed in the context of spin chains, which allows us to derive both, the deformed bulk and boundary/defect scattering matrices of integrable models. Using the deformed scattering matrices, we derive the flow equation for the deformed finite volume spectrum, as well as the cylinder partition function and the exact $g$-function.