activity
20062022
most citedAxion dark matter from topological defects

339 citations · 3k across the 59 of their papers we have counts for

collaborators

59 papers

astro-ph.CO2022★ 15 cited

Cosmological 21cm line observations to test scenarios of super-Eddington accretion on to black holes being seeds of high-redshifted supermassive black holes

Kazunori Kohri, Toyokazu Sekiguchi, Sai Wang

In this paper, we study scenarios of the super-Eddington accretion onto black holes at high redshifts , which are expected to be seeds to evolve to supermassive black holes…

astro-ph.CO2021★ 14 cited

tension without CMB data: beyond the CDM

Fumiya Okamatsu, Toyokazu Sekiguchi, Tomo Takahashi

We investigate the tension in a range of extended model frameworks beyond the standard CDM without the data from cosmic microwave background (CMB). Specifically, we adopt…

astro-ph.CO2021★ 38 cited

Revisiting CMB constraints on dark matter annihilation

Masahiro Kawasaki, Hiromasa Nakatsuka, Kazunori Nakayama +1

The precision measurements of the cosmic microwave background power spectrum put a strong constraint on the dark matter annihilation cross section since the electromagnetic energy…

astro-ph.CO2021★ 13 cited

Impacts of new small-scale N-body simulations on dark matter annihilations constrained from cosmological 21cm line observations

Nagisa Hiroshima, Kazunori Kohri, Toyokazu Sekiguchi +1

We revisit constraints on annihilating dark matter based on the global 21cm signature observed by EDGES. For this purpose, we used the numerical data of the latest N-body simulatio…

astro-ph.CO2020★ 16 cited

Cosmological bound on neutrino masses in the light of tension

Toyokazu Sekiguchi, Tomo Takahashi

Although cosmic microwave background (CMB) is the most powerful cosmological probe of neutrino masses, it is in trouble with local direct measurements of , which is called the…

astro-ph.CO2020★ 110 cited

Early recombination as a solution to the tension

Toyokazu Sekiguchi, Tomo Takahashi

We show that the tension can be resolved by making recombination earlier, keeping the fit to cosmic microwave background (CMB) data almost intact. We provide a suite of gener…