Naoki Tsukamoto

activity

20242026

most citedConstraints on the black-hole charges of M87* and Sagittarius A* by changing rates of photon spheres can be relaxed

13 citations · 24 across the 6 of their papers we have counts for

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gr-qc2025★ 2 cited

Gravitational lensing inside and outside of a marginally unstable photon sphere in a general, static, spherically symmetric, and asymptotically-flat spacetime in strong deflection limits

Naoki Tsukamoto

It is believed that rays bent inside and outside photon spheres could affect partially the black hole shadow images by the Event Horizon Telescope and the rays near photon spheres…

gr-qc2025

Linear perturbations of dyonic black holes in the lowest-order $U (1)$ gauge-invariant scalar-vector-tensor theories

Kitaro Taniguchi, Shunta Nishimura, Naoki Tsukamoto +1

We study linear perturbations on top of the static and spherically symmetric background of dyonic black hole solutions endowed with electric and magnetic charges, as well as a scal…

Gravitational lensing inside and outside of a marginally unstable photon sphere in a general, static, spherically symmetric, and asymptotically-flat spacetime in strong deflection limits

Linear perturbations of dyonic black holes in the lowest-order U(1) gauge-invariant scalar-vector-tensor theories

Linear perturbations of dyonic black holes in the lowest-order $U (1)$ gauge-invariant scalar-vector-tensor theories