activity
20242026
collaborators

5 papers

gr-qc2026

Relativistic frequency shifts in gravitational waves from axion clouds

Takuya Takahashi

Superradiant instability of ultralight bosons can produce clouds around rotating black holes, whose continuous gravitational wave (GW) emission is a promising observational target.…

gr-qc2025

Resonant DM scattering in the galactic center under the influence of EMRI

Takafumi Kakehi, Hidetoshi Omiya, Takuya Takahashi +1

Dark matter (DM) search is one of the greatest challenges in physics. If DM consists of particles, it may form a spike around supermassive black holes (BH) prevalent in galaxy cent…

gr-qc2024

Self-interacting axion clouds around rotating black holes in binary systems

Takuya Takahashi, Hidetoshi Omiya, Takahiro Tanaka

Superradiant instability can form clouds around rotating black holes (BHs) composed of ultralight bosonic fields, such as axions. A BH with such a cloud in a binary system exhibits…

astro-ph.CO2024

Soliton self-gravity and core-halo relation in fuzzy dark matter halos

Yusuke Manita, Takuya Takahashi, Atsushi Taruya

Fuzzy dark matter (FDM) is an attractive dark matter candidate composed of ultralight particles. In this paper, toward a clear understanding of the core-halo relation in the FDM ha…

gr-qc2024

Deci-Hz gravitational waves from the self-interacting axion cloud around the rotating stellar mass black hole

Hidetoshi Omiya, Takuya Takahashi, Takahiro Tanaka +1

Gravitational waves from condensates of ultra-light particles, such as axion, around rotating black holes are a promising probe to search for unknown physics. For this purpose, we…