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
9 papers · 1 filter
Power spectrum of domain-wall network and its implications for isotropic and anisotropic cosmic birefringence
Naoya Kitajima, Fumiaki Kozai, Fuminobu Takahashi +1
Recently, based on a novel analysis of the Planck satellite data, a hint of a uniform rotation of the polarization of cosmic microwave background photons, called isotropic cosmic b…
New scenario of QCD axion clump formation I: Linear analysis
Naoya Kitajima, Kazuhiro Kogai, Yuko Urakawa
The QCD axion acquires the potential through the non-perturbative effect of the QCD matters around the QCD phase transition. During this period, the direct interaction between the…
Primordial black holes in peak theory with a non-Gaussian tail
Naoya Kitajima, Yuichiro Tada, Shuichiro Yokoyama +1
In this paper, we update the peak theory for the estimation of the primordial black hole (PBH) abundance, particularly by implementing the critical behavior in the estimation of th…
Unified approach to secondary effects on the CMB B-mode polarization
Toshiya Namikawa, Atsushi Naruko, Ryo Saito +2
We develop a systematic and unified approach to estimate all possible secondary (i.e. non-primordial) nonlinear effects to the cosmic microwave background (CMB) polarization, named…
Nano-Hz gravitational wave signature from axion dark matter
Naoya Kitajima, Jiro Soda, Yuko Urakawa
We calculate the accurate spectrum of the stochastic gravitational wave background from U(1) gauge fields produced by axion dark matter. The explosive production of gauge fields so…
Gravitational Waves and Dark Radiation from Dark Phase Transition: Connecting NANOGrav Pulsar Timing Data and Hubble Tension
Yuichiro Nakai, Motoo Suzuki, Fuminobu Takahashi +1
Recent pulsar timing data reported by the NANOGrav collaboration may indicate the existence of a stochastic gravitational wave background around Hz. We explore a p…
Can axion clumps be formed in a pre-inflationary scenario?
Hayato Fukunaga, Naoya Kitajima, Yuko Urakawa
The QCD axion and an axion-like particle (ALP) are compelling candidates of dark matter. For the QCD axion, it is known that when the Peccei-Quinn (PQ) symmetry is spontaneously br…
Hunting Axion Dark Matter with Protoplanetary Disk Polarimetry
Tomohiro Fujita, Ryo Tazaki, Kenji Toma
We find that the polarimetric observations of protoplanetary disks are useful to search for ultra-light axion dark matter. Axion dark matter predicts the rotation of the linear pol…
Detectability of 21cm-signal during the Epoch of Reionization with 21cm-Lyman- emitter cross-correlation. I
Kenji Kubota, Shintaro Yoshiura, Keitaro Takahashi +5
Detection of the redshifted 21cm-line signal from neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) is complicated by intense foregrounds su…