Regularizing infrared divergences in de Sitter spacetime

• DOI: 10.48550/arxiv.2406.07610
• Publication Date: 2024-06-11
• Authors: Javier Huenupi; Ellie Hughes; Gonzalo A. Palma; Spyros Sypsas
• Keywords: High Energy Physics - Theory; High Energy Physics - Phenomenology; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); FOS: Physical sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

Correlation functions of light scalars in de Sitter space, computed standard perturbation theory, are hindered by time-dependent infrared divergences the form powers $\ln a(t)$, where $a(t)$ is scale factor describing expansion space. It has often been pointed out that loop corrections to these correlation make their divergence even stronger. In this note, we argue not case: Loop can be treated systematically with perturbative techniques (such as dimensional regularization) without necessarily introducing new a(t)$ dependencies. To concrete, focus on represented diagrams a single vertex and an arbitrary number loops. case, from loops removed counterterms order order, one finds observable loop-corrected indistinguishable tree-level form. By adopting Wilsonian perspective, further point our results favor use physical cutoffs (as opposed comoving cutoffs) regularize general vertices.