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BMy. CepHH 3. OH3HKA. ACTPOHOMHfl. 2022. №2
_ GRAVITY _
Visualization of Black Hole Images
V. I. Dokuchaev E-mail: dokuchaev@inr.ac.ru Institute for Nuclear Research of the Russian Academy of Sciences. Moscow, Russia
Received December 22, 2021
A fast progress in the observational technologies in astrophysics provides the unique possibility for detailed observations of black holes in the nearest future. It would be possible to verify general relativity and its numerous modifications in the strong field limit by using observational data from the advanced cosmic interferometric observatories. We review the modeled images of the rotating black hole in different appropriate cases: the luminous distant background, the thin accreting disk and the luminous moving hot spots in relativistic jets along the black hole rotation axis.
Keywords: black hole, astrophysics, general relativity.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 327-331.
Black Hole Information
Jihn E. Kim1'2 E-mail: jihnekim@gmail.com
1 Department of Physics, Seoul National University. Seoul, 08826 Republic of Korea 2Department of Physics, Kyung Hee University. Seoul 02447, Republic of Korea Received December 22, 2021
Information of a blackhole inside has a long history. After mentioning the original information idea, we show that local gauge invariance can connect the inside information to the outside surface area due to the Sperner's lemma.
Keywords: blackhole, sperner's lemma, entropy.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 332-325.
Gravitational Waves over Arbitrary Background
L. Panasenko E-mail: l.vetoshkina@g.nsu.ru
Physics Department, Novosibirsk State University. Novosibirsk, Russia Received January 14, 2022
Equation for gravitational wave (GW) propagation over arbitrary curved spacetime is derived in the presented work. Two new terms are found which absent in the conventional homogeneous and isotropic Friedmann cosmology. In conclusion we emphasize that these new terms can significantly change the character of solutions and assume that one of the terms may be the cause of relic GW amplitude suppression.
Keywords: gravitational waves, arbitrary spacetime background, Einstein equation, relic gravitational waves.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 336-337.
Gravitational Interaction of the Cosmic String with Pointlike Particles
P. Spirin E-mail: salotop@list.ru
Physics Department, Lomonosov Moscow State University, Russia Received January 9, 2022
The gravitational interaction of spinless relativistic particle and infinitely thin cosmic string is considered within the classical linearized-theory framework. We compute the reciprocal action of the particle on the cosmic string. We derive the retarded string's excitation, which includes the longitudinal (with respect to the unperturbed-particle motion) and totally-transverse ) string perturbations.
Keywords: cosmic string, angular deficit, elastic scattering.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 338-340.
