“…In the next section we recall the CTP formalism, using a variation of the Keldyshbasis, and apply it to φ 3 theory on a de Sitter background (for other applications of the CTP formalism to interacting fields in cosmology see [39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56]). Subsequently we analyze contributions to correlation functions with small external momenta, that are generated after horizon exit (but still during inflation).…”