Quantum corrections to the primordial tensor spectrum: open EFTs & Markovian decoupling of UV modes

A bstract Perturbative quantum corrections to primordial power spectra are important for testing the robustness and regime of validity inflation as an effective field theory. Although this has been done extensively density spectrum (and, some extent, tensor spectrum) using loop corrections, we do so in open system approach problem. Specifically, calculate first-order gravitational wave due (cubic) interactions alone. We show that our results match expectations from standard only strict Markovian limit , therefore, establish a systematic way relax approximation future, is generally necessary systems.