1 citations · 1 across the 7 of their papers we have counts for
9 papers
Cosmic Birefringence from Large Lepton Asymmetry
Kentaro Kasai, Ippei Obata
Cosmic birefringence, the rotation of the polarization plane of CMB photons, provides an intriguing probe of physics beyond the Standard Model. In this paper, we investigate a vect…
Merger rate of initially clustered primordial black holes for the two-body channel
Kentaro Kasai, Masahiro Kawasaki, Kai Murai +1
Primordial black holes (PBHs) may form an initially clustered population depending on their production mechanism. Motivated by binary black-hole merger events observed by gravitati…
Microlensing events and primordial black holes in the axionlike curvaton model
Kentaro Kasai, Masahiro Kawasaki, Kai Murai +1
Recently, Subaru Hyper Suprime-Cam (HSC) observations found 12 candidates for microlensing events. These events can be explained by primordial black holes (PBHs) with masses of $10…
Primordial black hole formation from the merger of oscillons
Kentaro Kasai, Naoya Kitajima
We show that the merger of oscillons results in a broad spectrum of the oscillon mass. A huge number of oscillon samples obtained from numerical lattice simulations reveal that the…
Resonant production of sterile neutrino dark matter with a refined numerical scheme
Kentaro Kasai, Masahiro Kawasaki, Kai Murai
The existence of a large primordial neutrino asymmetry is an intriguing possibility, both observationally and theoretically. Such an asymmetry can lead to the resonant production o…
Gravitational Waves from Particles Produced from Bubble Collisions in First-Order Phase Transitions
Keisuke Inomata, Marc Kamionkowski, Kentaro Kasai +1
We discuss a new source of gravitational waves (GWs) from first-order phase transitions. The collisions of bubbles of the new phase can efficiently produce particles that couple to…
Supermassive black hole formation from Affleck-Dine mechanism with suppressed clustering on large scales
Kentaro Kasai, Masahiro Kawasaki, Kai Murai +1
We study a primordial black hole (PBH) formation model based on the framework of the inhomogeneous Affleck-Dine (AD) mechanism, which can explain the seeds of supermassive black ho…
Affleck-Dine leptogenesis scenario for resonant production of sterile neutrino dark matter
Kentaro Kasai, Masahiro Kawasaki, Kai Murai
Sterile neutrino is a fascinating candidate for dark matter. In this paper, we examine the Affleck-Dine (AD) leptogenesis scenario generating a large lepton asymmetry, which can in…
Primordial Origin of Supermassive Black Holes from Axion Bubbles
Kentaro Kasai, Masahiro Kawasaki, Naoya Kitajima +3
We study a modification of the primordial black hole (PBH) formation model from axion bubbles. We assume that the Peccei-Quinn scalar rolls down in the radial direction from a larg…