4 papers
Detectability and Template Distinguishability of the Dark Ages 21 cm Global Signal with Wide and Sparse Frequency Coverage
Shintaro Yoshiura, Fumiya Okamatsu, Tomo Takahashi
The Dark Ages 21cm signal, observed at frequencies below 50 MHz, can serve as a powerful probe of cosmology, as the standard cosmological model predicts a well-defined 21cm spectra…
Super-critical primordial black hole formation via delayed first-order electroweak phase transition
Katsuya Hashino, Shinya Kanemura, Tomo Takahashi +2
The delay of the first-order electroweak phase transitions (EWPT) may lead to the emergence of baby universes inside wormhole structures due to the large vacuum energy density in f…
Constraints on sterile neutrinos and the cosmological tensions
Supriya Pan, Osamu Seto, Tomo Takahashi +1
We investigate cosmological bounds on sterile neutrino masses in the light of the Hubble and tensions. We argue that non-zero masses for sterile neutrinos are inferred at 2$Ï…
Kurtosis consistency relation in large-scale structure as a probe of gravity theories
Sora Yamashita, Takahiko Matsubara, Tomo Takahashi +1
Various gravity theories beyond general relativity have been rigorously investigated in the literature such as Horndeski and degenerate higher-order scalar-tensor (DHOST) theories.…