254 citations · 1.8k across the 51 of their papers we have counts for
4 papers · 1 filter
Relic Abundance of Dark Photon Dark Matter
Prateek Agrawal, Naoya Kitajima, Matthew Reece +2
We present a new mechanism for producing the correct relic abundance of dark photon dark matter over a wide range of its mass, extending down to . The dark m…
Gravitational wave forest from string axiverse
Naoya Kitajima, Jiro Soda, Yuko Urakawa
Axions predicted in string theory may have a scalar potential which has a much shallower potential region than the conventional cosine potential. We first show that axions which we…
Electromagnetic effects induced by time-dependent axion field
Katsuhisa Taguchi, Tatsushi Imaeda, Tetsuya Hajiri +4
We studied the dynamics of the so-called -term, which exists in topological materials and is related to a hypothetical field predicted by Peccei-Quinn in particle physics, in a…
Distribution of primordial black holes and 21cm signature
Jinn-Ouk Gong, Naoya Kitajima
We show that the number of primordial black holes (PBHs) which is originated from primordial density perturbations with moderately-tilted power spectrum fluctuates following the lo…