Cosmological inflation, effective field theory, and symmetry breaking

I’ll present new applications of effective field theory — a standard tool in particle physics and condensed matter — to early universe inflation. Requiring only to specify which symmetries are broken during the inflationary era, effective field theory provides a powerful method for analyzing the predictions of inflation in a model independent and general way. I’ll discuss the possibility of breaking full diffeomorphism invariance during inflation, and its observable consequences for the properties of primordial gravitational waves produced in the inflationary era.