Cutting cosmological correlators

The initial conditions of our universe appear to us in the form a classical probability distribution that we probe with cosmological observations. In current leading paradigm, this arises from quantum mechanical wavefunction universe. Here ask what imprint mechanics is on late time observables. We show requirement unitary evolution, colloquially conservation probabilities, fixes analytic structure and all correlators it encodes. particular, derive perturbation theory an infinite set single-cut rules generalize Cosmological Optical Theorem relate certain discontinuity any tree-level $n$-point function lower-point functions. Our are closely related to, but distinct recently derived Cutting Rules. They follow choice Bunch-Davies vacuum simple property (bulk-to-bulk) propagator astoundingly general: prove they valid for fields linear dispersion relation mass, integer spin arbitrary local interactions number derivatives. also apply general FLRW spacetimes admitting vacuum, including de Sitter, slow-roll inflation, power-law cosmologies even resonant oscillations axion monodromy. verify non-trivial examples, four massless scalars exchanging massive scalar, as relevant collider physics, gravitons graviton, scalar five-point function.