Single field models of inflation capable to produce primordial black holes usually require a significant departure from the standard, perturbative slow-roll regime. In fact, in many of these scenarios, the size of the slow-roll parameter ∣η∣ becomes larger than one during a short phase of inflationary evolution. In order to develop an analytical control on these systems, the speaker explores the limit of ∣η∣ large, and promote 1/∣η| to a small quantity to be used for perturbative expansions. Formulas simplify, and analytic expressions for the two- and three-point functions of curvature fluctuations are obtained. He will then discuss the behavior of loop corrections to inflationary observables in this framework.
頻道：Zoom ID:421-480-1692 ← cosmology
講者：Gianmassimo Tasinato (Universita di Bologna & Swansea University)
“Copernicus Webinar and Colloquium Series”: To promote scientific discussions during this pandemic, they are organizing an online seminar series, i.e. Copernicus Webinar Series, seeking the most outstanding speakers to introduce innovative ideas and important progress in the field of gravity and cosmology. This series is named after the famous Polish Astronomer, Nicolaus Copernicus, whose discovery eventually marked the dawn of modern science.