Graviton non-Gaussianity with non-Bunch-Davies initial conditionsConfirmed

by Maria Mylova (IPMU/PI)

Tuesday Sep 17, 2024, 11:00 a.m. → 12:30 p.m. America/Toronto

PI/4-405 - Bob Room (Perimeter Institute for Theoretical Physics)

I will discuss recent progress on the initial conditions for inflation and how this can potentially enhance gravitational wave non-Gaussianity (NG). In particular, there is a significant additional NG contribution in the flattened configuration, offering a straightforward way to boost parity-violating NG from Chern-Simons gravity, which typically suffers from graviton ghost-production. Furthermore, I will explore how this shape – at the level of the trispectrum – can enable direct measurement of NG in the stochastic gravitational wave background (SGWB) using pulsar timing arrays (PTA). This is particularly intriguing as it allows us to investigate NG at scales complementary to those observed in the CMB, which could help us distinguish between various early universe models and physical mechanisms.