Shadow in the Galactic Center: Theoretical Concept -- Prediction -- Realization

TL;DR

This paper reviews the development of relativistic astrophysics, focusing on black hole shadows, from theoretical concepts to observable phenomena, emphasizing recent observational confirmations in the Galactic Center and M87*.

Contribution

It provides a comprehensive overview of the evolution of black hole shadow research, highlighting recent observational realizations and their significance in testing General Relativity.

Findings

Black hole shadows have been observed in the Galactic Center and M87*.

Observational data confirms theoretical predictions of black hole shadows.

The evolution from theory to observation demonstrates progress in relativistic astrophysics.

Abstract

General Relativity (GR) was created in November 1915 and since its creation and up to now this theory has undergone many tests. The first realistic cosmological models were proposed in the works of Friedman, written in the 1920s. For a long time Friedman's cosmological works were actually banned in Soviet Union due to philosophical reasons, since the models where the birth and evolution of the Universe occurs were considered ideologically unacceptable. Due to great achievements in relativity and cosmology and due to increasing interest to these branches of of science in last decades we recall a development of relativistic astrophysics and contribution of Russian researchers in these studies. Since one of the world leaders in physical cosmology A. A. Friedman passed away in September 1925, it is reasonable to outline the main achievements of physical cosmology over the past 100 years. We discuss also observational and theoretical achievements in confirmations of relativistic observational predictions for black holes, including the closest supermassive black hole in our Galactic Center. We outline an evolution of black hole shadow from the purely theoretical concept to observable quantities for supermassive black holes in Sgr A* and M87*.