Description
Chair: Shinsuke Kawai (Sungkyunkwan University)
I describe difficulty of primordial black hole formation in single field inflation and its relevance to stochastic gravitational wave observation.
We present a new way to study cosmic inflation with gravitational waves. The gravitational signal is generated thanks to nonlinear structures in the inflaton field, called oscillons. This novel probe allows us to test models of inflation which are challenging to test with CMB experiments.
I shall discuss gravitational wave signatures coming from a single-field inflation model in which the inflaton couples to the Gauss-Bonnet term. When the scalar potential term and the Gauss-Bonnet coupling term have different signs, a nontrivial fixed point arises, effectively inducing ultra slow-roll inflation. In this case, primordial black holes can form, together with enhanced...
Gravitational Waves are an excellent way to probe the evolution of the universe way back before BBN. In particular, they offer a unique way to test modified Einstein equations. At the level of the equation of motion, the simplest example of Horndeski’s theory containing higher-curvature terms is the dilaton-Einstein-Gauss-Bonnet (dEGB) the- ory, obtained by adding a specific quadratic...
