2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/182955We discuss reflection factors for purely elastic scattering theories and relate them to perturbations of specific conformal boundary conditions, using recent results on exact off-critical g-functions. For the non-unitary cases, we support our conjectures using a relationship with quantum group reductions of the sine-Gordon model. Our results imply the existence of a variety of new flows between conformal boundary conditions, some of them driven by boundary-changing operators.45 pages, 7 figures. v2: minor typos corrected, 3 new references and some further discussion of the massless boundary flows includedHigh Energy Physics - TheoryStatistical MechanicsMathematical Physicstext