683 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Tohoku UniversityJP202 papers
- The University of TokyoJP78 papers
- Kyoto UniversityJP59 papers
- National Astronomical Observatory of JapanJP44 papers
- Kavli Institute for the Physics and Mathematics of the UniverseJP40 papers
- Nagoya UniversityJP33 papers
- The University of OsakaJP32 papers
- Massachusetts Institute of TechnologyUS30 papers
- Institute of Space and Astronautical ScienceJP27 papers
- Japan Aerospace Exploration AgencyJP26 papers
- Ehime UniversityJP24 papers
- Institute of Astronomy and Astrophysics, Academia SinicaTW24 papers
14 papers · 1 filter
Stability of domain wall network with initial inflationary fluctuations, and its implications for cosmic birefringence
Diego Gonzalez, Naoya Kitajima, Fuminobu Takahashi +1
We study the formation and evolution of domain walls with initial inflationary fluctuations by numerical lattice calculations that, for the first time, correctly take into account…
Wash-in leptogenesis after axion inflation
Valerie Domcke, Kohei Kamada, Kyohei Mukaida +2
CP violation and the violation of baryon-minus-lepton number B-L do not necessarily have to occur simultaneously in order to accomplish successful leptogenesis. Instead, it suffice…
Formation of hot spots around small primordial black holes
Minxi He, Kazunori Kohri, Kyohei Mukaida +1
In this paper, we investigate the thermalization of Hawking radiation from primordial black holes (PBHs) in the early Universe, taking into account the interference effect on therm…
Cascades of high-energy SM particles in the primordial thermal plasma
Kyohei Mukaida, Masaki Yamada
High-energy standard model (SM) particles in the early Universe are generated by the decay of heavy long-lived particles. The subsequent thermalization occurs through the splitting…
Gravitational production of dark photon dark matter with mass generated by the Higgs mechanism
Takanori Sato, Fuminobu Takahashi, Masaki Yamada
We study the gravitational production of dark photon dark matter during inflation, when dark photons acquire mass by the Higgs mechanism. In the previous study, it was assumed that…
Non-thermally trapped inflation by tachyonic dark photon production
Naoya Kitajima, Shota Nakagawa, Fuminobu Takahashi
We show that a dark Higgs field charged under U(1) gauge symmetry is trapped at the origin for a long time, if dark photons are produced by an axion condensate via tachyo…
Semiclassical analysis of axion-assisted and axion-driven pair production
Hiroyuki Kitamoto, Masaki Yamada
We study the pair production of fermions in a time dependent axion background with and without an electric background. We construct the adiabatic mode functions which incorporate t…
Cosmic Birefringence Triggered by Dark Matter Domination
Shota Nakagawa, Fuminobu Takahashi, Masaki Yamada
Cosmic birefringence is predicted if an axion-like particle (ALP) moves after the recombination. We show that this naturally happens if the ALP is coupled to the dark matter densit…
Trapping Effect for QCD Axion Dark Matter
Shota Nakagawa, Fuminobu Takahashi, Masaki Yamada
In the early universe, the potential of a scalar field can be significantly modified, and the scalar field may be trapped for a long time in a different location than the current v…
What if ALP dark matter for the XENON1T excess is the inflaton
Fuminobu Takahashi, Masaki Yamada, Wen Yin
The recent XENON1T excess in the electron recoil data can be explained by anomaly-free axion-like particle (ALP) dark matter with mass keV and the decay constan…
Primordial Black Holes from QCD Axion Bubbles
Naoya Kitajima, Fuminobu Takahashi
We propose a scenario in which a strong Peccei-Quinn (PQ) symmetry breaking in the early universe results in large inhomogeneities of the initial QCD axion field value, leading to…
XENON1T excess from anomaly-free ALP dark matter and its implications for stellar cooling anomaly
Fuminobu Takahashi, Masaki Yamada, Wen Yin
Recently, an anomalous excess was found in the electronic recoil data collected at the XENON1T experiment. The excess may be explained by an axion-like particle (ALP) with mass of…
Strongly-interacting massive particle and dark photon in the era of intensity frontier
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
A strongly interacting massive particle (SIMP) is an interesting candidate for dark matter (DM) because its self-interaction cross section can be naturally strong enough to address…
Stochastic inflation with an extremely large number of -folds
Naoya Kitajima, Yuichiro Tada, Fuminobu Takahashi
We propose a class of single-field, slow-roll inflation models in which a typical number of -folds can be extremely large. The key point is to introduce a very shallow local min…