Falsification of gravity theories from the form of dark spots on black hole images

Visual images of supermassive black holes M87* and SgrA* have been successfully registered recently by the international collaboration Event Horizon Telescope. This registration opens the unique possibility for verification (or falsification) of modified gravity theories in the strong filed limit when gravitational field is dominated over astrophysical factors. This verification is crucially important for physical interpretation of astrophysical and cosmological observations of the Universe and for understanding the physical origin of enigmatic dark matter and dark energy. The accuracy of Event Horizon Telescope is sufficient for demonstration of the quantitative agreement of the obtained dark spot images of both black holes with the General Relativity prediction. In particular, the forms of dark spots on the Event Horizon Telescope images correspond to the fast black hole rotation of the supermassive black holes M87* and SgrA*. Meantime, the Event Horizon Telescope accuracy is insufficient for the verification of the modified gravity theories. In the observable future this verification would be possible in realization of the international project of the Space Observatory Millimetron, which angular resolution in few orders of magnitude exceeds the corresponding one of the Event Horizon Telescope.