Density matrix and generating functional for quantized neutrino field in the space-time of a rotating black hole

1989 ◽  
Vol 78 (1) ◽  
pp. 31-41 ◽  
Author(s):  
P. A. Bolashenko ◽  
V. P. Frolov
Keyword(s):  
Black Hole ◽  
Density Matrix ◽  
Space Time ◽  
Generating Functional ◽  
Rotating Black Hole ◽  
Neutrino Field

Super-Penrose process

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040058
Author(s):  
O. B. Zaslavskii
Keyword(s):  
Black Hole ◽  
Flat Space ◽  
Space Time ◽  
Centre Of Mass ◽  
Rotating Black Hole ◽  
Mass Frame ◽  
Penrose Process ◽  
Energy Formula ◽  
Full Classification

If two particles collide near a rotating black hole, their energy in the centre of mass frame can become unbounded under certain conditions. In doing so, the Killing energy [Formula: see text] of debris at infinity is, in general, remain restricted. If [Formula: see text] is also unbounded, this is called the super-Penrose process. We elucidate when such a process is possible and give full classification of corresponding relativistic objects for rotating space-times. We also discuss the case of a pure electric super-Penrose process that is valid even in the flat space-time. The key role in consideration is played by the Wald inequalities.

scholarly journals Particles with Negative Energies in Nonrelativistic and Relativistic Cases

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 528
Author(s):  
Andrey A. Grib ◽  
Yuri V. Pavlov
Keyword(s):  
Black Hole ◽  
Coordinate System ◽  
Space Time ◽  
De Sitter ◽  
Relativistic Case ◽  
Nonrelativistic Case ◽  
Rotating Black Hole ◽  
Minkowski Space Time ◽  
Penrose Process ◽  
Penrose Effect

States of particles with negative energies are considered for the nonrelativistic and relativistic cases. In the nonrelativistic case it is shown that the decay close to the attracting center can lead to the situation similar to the Penrose effect for a rotating black hole when the energy of one of the fragments is larger than the energy of the initial body. This is known as the Oberth effect in the theory of the rocket movement. The realizations of the Penrose effect in the non-relativistic case in collisions near the attracting body and in the evaporation of stars from star clusters are indicated. In the relativistic case similar to the well known Penrose process in the ergosphere of the rotating black hole it is shown that the same situation as in ergosphere of the black hole occurs in rotating coordinate system in Minkowski space-time out of the static limit due to existence of negative energies. In relativistic cases differently from the nonrelativistic ones, the mass of the fragment can be larger than the mass of the decaying body. Negative energies for particles are possible in the relativistic case in cosmology of the expanding space when the coordinate system is used with a nondiagonal term in metrical tensor of the space-time. Friedmann metrics for three cases: open, close and quasieuclidian, are analyzed. The De Sitter space-time is shortly discussed.

scholarly journals Dynamics of the nonrotating and rotating black hole scalarization

2021 ◽  
Vol 103 (6) ◽  
Author(s):  
Daniela D. Doneva ◽  
Stoytcho S. Yazadjiev
Keyword(s):  
Black Hole ◽  
Rotating Black Hole

scholarly journals Global aspects of accelerating and rotating black hole spacetimes

2005 ◽  
Vol 23 (2) ◽  
pp. 555-568 ◽  
Author(s):  
J B Griffiths ◽  
J Podolský
Keyword(s):  
Black Hole ◽  
Rotating Black Hole ◽  
Black Hole Spacetimes
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