462 citations · 2.2k across the 34 of their papers we have counts for
7 papers · 1 filter
Formation of intermediate-mass black holes as primordial black holes in the inflationary cosmology with running spectral index
Toshihiro Kawaguchi, Masahiro Kawasaki, Tsutomu Takayama +2
Formation of primordial black holes (PBHs) on astrophysical mass scales is a natural consequence of inflationary cosmology if the primordial perturbation spectrum has a large and n…
Cosmological implications of supersymmetric axion models
Masahiro Kawasaki, Kazunori Nakayama, Masato Senami
We derive general constraints on supersymmetric extension of axion models, in particular paying careful attention to the cosmological effects of saxion. It is found that for every…
Solving the cosmic lithium problems with primordial late-decaying particles
Daniel Cumberbatch, Kazuhide Ichikawa, Masahiro Kawasaki +3
We investigate the modifications to predictions for the abundances of light elements from standard Big-Bang nucleosynthesis when exotic late-decaying particles with lifetimes excee…
Cosmological Constraints on Isocurvature and Tensor Perturbations
Masahiro Kawasaki, Toyokazu Sekiguchi
We investigate cosmological constraints on primordial isocurvature and tensor perturbations, using recent observations of the cosmic microwave background and the large scale struct…
Cosmological Constraints on Neutrino Injection
Toru Kanzaki, Masahiro Kawasaki, Kazunori Kohri +1
We derive general constraints on the relic abundances of a long-lived particle which mainly decays into a neutrino (and something else) at cosmological time scales. Such an exotic…
Baryon Asymmetry in a Heavy Moduli Scenario
Masahiro Kawasaki, Kazunori Nakayama
In some models of supersymmetry breaking, modulus fields are heavy enough to decay before BBN. But the large entropy produced via moduli decay significantly dilutes the preexisting…