Do the edges of inflation leave marks on the universe?

Most calculations of primordial signals from inflation focus on particle interactions deep in spacetime, ignoring effects at inflation's end. This paper shows boundary terms are not always negligible — some produce genuinely independent contributions to the statistical patterns imprinted on the sky. By connecting boundary terms to field redefinitions, they derive a precise test for when boundaries matter, then work out concrete examples for massive-particle exchange, including theories that break de Sitter symmetry.