242 citations · 533 across the 16 of their papers we have counts for
5 papers · 1 filter
QCD Axion Dark Matter from level crossing with refined adiabatic condition
Kai Murai, Yuma Narita, Fuminobu Takahashi +1
We investigate the level-crossing phenomenon in two-axion systems, where the mass eigenvalues intersect as the mass of one axion increases with the cooling of the universe. This ph…
A Bound on Light Dark Photon Dark Matter
Naoya Kitajima, Shota Nakagawa, Fuminobu Takahashi +1
We derive a bound on dark photon dark matter scenarios where the dark photon mass is generated through the Higgs mechanism, based on the requirement that symmetry breaking must occ…
More is Different: Multi-Axion Dynamics Changes Topological Defect Evolution
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We study topological defects in multi-axion models arising from multiple Peccei-Quinn (PQ) scalars. Using a simplified two-axion system, we reveal fundamental differences in the ev…
Induced Domain Walls of QCD Axion, and Gravitational Waves
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We show that heavy axion domain walls induce domain walls of the QCD axion through a mixing between the heavy axion and the QCD axion, even when the pre-inflationary initial condit…
Bubble Misalignment Mechanism for Axions
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We study the dynamics of axions at first-order phase transitions in non-Abelian gauge theories. When the duration of the phase transition is short compared to the timescale of the…