Irrelevant deformations with boundaries and defects

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