3 citations · 4 across the 11 of their papers we have counts for
11 papers
Reviving the Affleck-Dine Curvaton Scenario with Compensated Isocurvature Perturbations
Masahiro Kawasaki, Shunsuke Neda
We revisit the Affleck-Dine curvaton scenario in the framework of supersymmetry, taking Q-ball formation into account. In this scenario, a scalar field carrying baryon number, name…
Lattice study of primordial black hole formation in bumpy axion inflation
Masahiro Kawasaki, Kai Murai, Shunsuke Tsuchida
We study primordial black hole (PBH) formation in axion inflation using lattice simulations. In axion inflation with a bumpy potential, the curvature perturbations ca…
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…
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…
EMPRESS. XV. A New Determination of the Primordial Helium Abundance Suggesting a Moderately Low Value
Hiroto Yanagisawa, Masami Ouchi, Akinori Matsumoto +18
We present a new constraint on the primordial helium abundance, , based on Subaru observations. A major source of uncertainty in previous determination…
Q-balls Under Spontaneously Broken U(1) Symmetry
Masahiro Kawasaki, Kai Murai, Fuminobu Takahashi
We study the evolution of Q-balls under a spontaneously broken global symmetry. Q-balls are stabilized by the conservation of charge, but when the symmetry is spontan…
EMPRESS. X. Spatially resolved mass-metallicity relation in extremely metal-poor galaxies: evidence of episodic star-formation fueled by a metal-poor gas infall
Kimihiko Nakajima, Masami Ouchi, Yuki Isobe +47
Using the Subaru/FOCAS IFU capability, we examine the spatially resolved relationships between gas-phase metallicity, stellar mass, and star-formation rate surface densities (Sigma…
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…
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
Yuki Isobe, Masami Ouchi, Kimihiko Nakajima +49
We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities () and low stellar masses (). Tak…