TPPC weekly seminar (in-person): Mariana Carrillo Gonzalez - Causality bounds in cosmology

Wednesday 9 Apr 2025, 12:45 → 14:00 Europe/London

S7.06

Effective field theories (EFTs) provide a framework to parameterize our ignorance of UV physics using Wilson coefficients, which are not assigned a priori values. However, certain values of these coefficients can lead to unphysical outcomes. In this talk, I will review how causal propagation in the IR can give bounds on EFTs. Then, I will explain how this criterion can be applied to cosmological spacetime. I will show explicit constraints on shift symmetric scalars in de Sitter and on the EFT of inflation. The latter analysis focuses on models where there is a large growth in the power spectrum of the curvature fluctuations. Such models are particularly interesting as they can produce primordial black holes and scalar-induced gravitational waves.