16 papers
Revisiting constraints on magnetogenesis from baryon asymmetry
Yuta Hamada, Kyohei Mukaida, Fumio Uchida
Magnetic fields in the universe potentially serve as a messenger of primordial physics. The observationally suggested intergalactic magnetic fields may be a relic of helical primor…
Reheating with Thermal Dissipation and Primordial Gravitational Waves
Kazuma Minami, Kyohei Mukaida, Kazunori Nakayama
In order for an inflationary universe to evolve into a hot universe, a process known as reheating is required. However, the precise mechanism of reheating remains unknown. We show…
Revisiting unitarity of single scalar field with non-minimal coupling
Minxi He, Muzi Hong, Kyohei Mukaida +1
We have investigated the unitarity violation scale of a non-minimally coupled scalar field with quartic self-coupling. This model is widely studied in the literature but the estima…
Cancellation of loop corrections to soft scalar power spectrum
Yohei Ema, Muzi Hong, Ryusuke Jinno +1
We prove the absence of scale-invariant one-loop corrections to the superhorizon curvature perturbations from small-scale (potentially enhanced) scalar perturbations in a general i…
No-scale Brans-Dicke Gravity -- ultralight scalar boson & heavy inflaton
Muzi Hong, Kyohei Mukaida, Tsutomu T. Yanagida
It is very much intriguing if the Planck scale is not a fundamental parameter. The Brans-Dicke gravity is nothing but the theory where the Planck scale …
Cancellation of one-loop correction to soft tensor power spectrum
Yohei Ema, Muzi Hong, Ryusuke Jinno +1
We demonstrate that there are no scale-invariant one-loop corrections to the superhorizon tensor perturbations from small-scale (potentially enhanced) scalar perturbations, irrespe…