67 citations · 355 across the 27 of their papers we have counts for
9 papers · 1 filter
CMB distortion anisotropies due to the decay of primordial magnetic fields
Koichi Miyamoto, Toyokazu Sekiguchi, Hiroyuki Tashiro +1
We investigate the power spectrum of the distortion of Cosmic Microwave Background (CMB) due to the decay of the primordial magnetic fields. It is known that there are two-types of…
Cosmological and astrophysical constraints on superconducting cosmic strings
Koichi Miyamoto, Kazunori Nakayama
We investigate the cosmological and astrophysical constraints on superconducting cosmic strings (SCSs). SCS loops emit strong bursts of electromagnetic waves, which might affect va…
Forecast constraints on cosmic strings from future CMB, pulsar timing and gravitational wave direct detection experiments
Sachiko Kuroyanagi, Koichi Miyamoto, Toyokazu Sekiguchi +2
We study future observational constraints on cosmic string parameters from various types of next-generation experiments: direct detection of gravitational waves (GWs), pulsar timin…
Non-Gaussian isocurvature perturbations in dark radiation
Etsuko Kawakami, Masahiro Kawasaki, Koichi Miyamoto +2
We study non-Gaussian properties of the isocurvature perturbations in the dark radiation, which consists of the active neutrinos and extra light species, if exist. We first derive…
Forecast constraints on cosmic string parameters from gravitational wave direct detection experiments
Sachiko Kuroyanagi, Koichi Miyamoto, Toyokazu Sekiguchi +2
Gravitational waves (GWs) are one of the key signatures of cosmic strings. If GWs from cosmic strings are detected in future experiments, not only their existence can be confirmed…
Isocurvature perturbations in extra radiation
Masahiro Kawasaki, Koichi Miyamoto, Kazunori Nakayama +1
Recent cosmological observations, including measurements of the CMB anisotropy and the primordial helium abundance, indicate the existence of an extra radiation component in the Un…
Kahler moduli double inflation
Masahiro Kawasaki, Koichi Miyamoto
We show that double inflation is naturally realized in Kähler moduli inflation, which is caused by moduli associated with string compactification. We find that there is a small cou…
B-mode polarization induced by gravitational waves from kinks on infinite cosmic strings
Masahiro Kawasaki, Koichi Miyamoto, Kazunori Nakayama
We investigate the effect of the stochastic gravitational wave (GW) background produced by kinks on infinite cosmic strings, whose spectrum was derived in our previous work, on the…
Gravitational waves from kinks on infinite cosmic strings
Masahiro Kawasaki, Koichi Miyamoto, Kazunori Nakayama
Gravitational waves emitted by kinks on infinite strings are investigated using detailed estimations of the kink distribution on infinite strings. We find that gravitational waves…