24 citations · 76 across the 6 of their papers we have counts for
6 papers
Stochastic inflation with gradient interactions
Vadim Briaud, Ryodai Kawaguchi, Vincent Vennin
Stochastic inflation rests on the separate-universe approximation, i.e. the ability to describe long-wavelength fluctuations in an inflating universe as homogeneous perturbations o…
Effective Field Theory of Chiral Gravitational Waves
Katsuki Aoki, Tomohiro Fujita, Ryodai Kawaguchi +1
When a (non-)Abelian gauge field acquires an isotropic background configuration during inflation, strong gravitational waves (GWs) with parity-violating polarization, known as chir…
Dip and non-linearity in the curvature perturbation from inflation with a transient non-slow-roll stage
Tomohiro Fujita, Ryodai Kawaguchi, Misao Sasaki +1
We consider models of inflation that contain a transient non-slow-roll stage and investigate the conditions under which a dip appears in the power spectrum of the curvature perturb…
Proving the absence of large one-loop corrections to the power spectrum of curvature perturbations in transient ultra-slow-roll inflation within the path-integral approach
Ryodai Kawaguchi, Shinji Tsujikawa, Yusuke Yamada
We revisit one-loop corrections to the power spectrum of curvature perturbations in an inflationary scenario containing a transient ultra-slow-roll (USR) period. In Ref.[1], it…
Roles of boundary and equation-of-motion terms in cosmological correlation functions
Ryodai Kawaguchi, Shinji Tsujikawa, Yusuke Yamada
We revisit the properties of total time-derivative terms as well as terms proportional to the free equation of motion (EOM) in a Schwinger-Keldysh formalism. They are relevant to t…
Starobinsky inflation with a quadratic Weyl tensor
Antonio De Felice, Ryodai Kawaguchi, Kotaro Mizui +1
In Starobinsky inflation with a Weyl squared Lagrangian , where is a coupling constant, we study the linear stability of cosmological perturbations on a spatially flat F…