Effective field theory in de Sitter space and the method of regions

• Andrea Sanfilippo (Technical University of Munich)

Room: 4/3-006 - TH Conference Room Understanding the infrared dynamics of light and massless fields in de Sitter space remains an important open problem. When computed in perturbation theory, the in-in correlation functions are plagued by infrared divergences and secularly growing terms. The Soft de Sitter Effective Theory (SdSET) was developed as a framework in which these issues can be addressed. However, some important technical aspects of the SdSET remain unexplored. In this talk, I will show how the Method of Regions can be applied to cosmological correlators to elucidate the structure of the SdSET and to simplify the necessary matching computations to determine the free parameters of the EFT. I will then discuss the field-theoretical foundations of SdSET, how matching computations can be performed systematically and how the issues of IR-divergences and secular growth can be addressed from an EFT point of view.