pith. sign in

arxiv: 1805.03311 · v2 · pith:XI5PZ7IAnew · submitted 2018-05-08 · 🌀 gr-qc

Shadow of a black hole at cosmological distance

Gennady S. Bisnovatyi-Kogan , Oleg Yu. Tsupko This is my paper
classification 🌀 gr-qc
keywords blackshadowsizeholeuniverseapproachcasecosmological
0
0 comments X
read the original abstract

Cosmic expansion is expected to influence on the size of black hole shadow observed by comoving observer. Except the simplest case of Schwarzschild black hole in de Sitter universe, analytical approach for calculation of shadow size in expanding universe is still not developed. In this paper we present approximate method based on using angular size redshift relation. This approach is appropriate for general case of any multicomponent universe (with matter, radiation and dark energy). In particular, we have shown that supermassive black holes at large cosmological distances in the universe with matter may give a shadow size approaching to the shadow size of the black hole in the center of our galaxy, and present sensitivity limits.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Shaving off soft hairs and the black hole image memory effect

    gr-qc 2026-03 unverdicted novelty 7.0

    Soft-haired Kerr black holes show rotated, dilated, drifting images and an image memory effect when soft hair changes via waves, with the effect scaling with the large black hole's mass and spin.

  2. Shadows of Giants: Constraints on Stupendously Large Black Holes from Negative Sources against the Cosmic Microwave Background

    astro-ph.CO 2026-02 unverdicted novelty 7.0

    Stupendously large black holes cast shadows on the CMB that rule out masses above 10^17 solar masses within the last scattering surface and limit their density parameter to below 10^-5 for masses 10^15 to 10^18 solar masses.

  3. Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A$^*$

    gr-qc 2022-05 conditional novelty 5.0

    EHT observations of Sgr A* constrain deviations from GR black hole solutions including regular BHs, string-inspired spacetimes, and BH mimickers, with some limits exceeding cosmological bounds.

  4. Probing Kalb-Ramond gravity with charged rotating black holes: constraints from EHT observations

    gr-qc 2026-04 unverdicted novelty 3.0

    EHT shadow observations constrain the Lorentz-violating parameter ℓ in Kalb-Ramond gravity for charged rotating black holes to roughly |ℓ| ≲ 0.1-0.2, with an upper bound ℓ ≲ 0.19 from Sgr A*.