759 citations · 4.7k across the 147 of their papers we have counts for
150 papers
Limited Impact of CMB B-mode Polarization on Constraints on Cosmic Topology
Ryota Himeno, Atsushi J. Nishizawa, Kiyotomo Ichiki
The global spatial structure of the universe is a fundamental question in cosmology. Although the standard model usually assumes a trivial topology, a multiply connected universe c…
Standard Reconstruction Shifts the Optimal Input Scale for CNN-Based Density-Field Reconstruction
Koichiro Nakashima, Kiyotomo Ichiki, Atsushi J. Nishizawa
We investigate convolutional neural network (CNN) methods for reconstructing the high-redshift density field from late-time large-scale structure, focusing on how the physical scal…
Turbulent Transport of Galactic Magnetic Fields into Cosmic Voids: Insights from IllustrisTNG
Yuri Yamashita, Hiroyuki Tashiro, Kiyotomo Ichiki
Astrophysical processes associated with galaxies may contribute to the magnetization of cosmic voids. We investigate the diffusion of galactic magnetic fields in an expanding unive…
Revisiting constraints on primordial vector modes and implications for sourced magnetic fields and observed power spectrum
Kaito Yura, Shohei Saga, Shuichiro Yokoyama +1
We revisit regular primordial vector modes sustained by the anisotropic stress of free-streaming neutrinos. We consider two classes of neutrino-sector initial conditions, the neutr…
Inferring population III star properties from the 21-cm global signal
Sho Ukai, Hayato Shimabukuro, Kenji Hasegawa +1
Investigating the properties of the first stars in the universe, known as Population III (Pop~III) stars, is essential, yet it remains an open question. One way to explore these st…
Quintessence with tachyonic resonance and late-time cosmic-microwave-background and gravitational-wave signals
Shun Yoshioka, Kiyotomo Ichiki, Yuichiro Tada +1
Combinations of recent cosmological observations, including Dark Energy Spectroscopic Instrument (DESI), show hints of a dynamical nature for dark energy. While the data suggest th…