2 papers
gr-qc2025
Shadow formation in gravitational collapse: Redshift and blueshift by spacetime dynamics
Yasutaka Koga, Nobuyuki Asaka, Masashi Kimura +1
A black hole illuminated by a background light source is observed as a black hole shadow. For a black hole formed by gravitational collapse of a transmissive object, redshift of li…
gr-qc2025
Gravitational mode mixing around black holes in scalar-tensor theories with parity-violating terms
Shin'ichi Hirano, Masashi Kimura, Masahide Yamaguchi
We investigate black holes and gravitational perturbations when both the scalar Gauss-Bonnet and dynamical Chern-Simons gravity sectors coexist in addition to the Einstein-Hilbert…