34 research outputs found
Curved spacetime as a dispersive multiferroic medium for an electromagnetic wave: polarization and magnetization vectors in the Schwarzschild spacetime
We study one of the interesting properties of the electromagnetic wave
propagation in the curved Schwarzschild background spacetime in the framework
of general relativity (GR). The electromagnetic wave equation has been derived
from vacuum general relativistic Maxwell's equations. It is shown that the
solutions for the electromagnetic field can be expanded in the spherical
harmonic functions and all components of the electromagnetic fields can be
expressed in terms of two radial profile functions. These radial profile
functions can be expressed in terms of the confluent Heun function. The
calculated behaviour of the electric and magnetic susceptibilities near the
event horizon appears to be similar to the susceptibilities of multiferroic
materials near phase transition. The Curie temperature of this phase transition
appears to coincide with the Hawking temperature.Comment: 11 pages, 3 figures, to be accepted to Chinese Journal of Physic
Generalized evaluations in sociological researches
Considered the calculation of generalized evaluations in heterogeneous characteristic space. Methods of data mining are used for calculating generalized evaluations
Gravitational synchrotron radiation and Penrose process in STVG theory
The paper has explored analogue of gravitational synchrotron massive particle
and Penrose process in MOdified Gravity (MOG) known as
Scalar-Tensor-Vector-Gravity (STVG). Investigation of the gravitational field
around Kerr-MOG black hole showed that it has strong gravitational field with
large horizon and can rotate faster than Kerr black hole due to the effect of
STVG. We have studied influence of STVG in circular motion of massive particle
around Kerr-MOG black hole and discussed the Innermost Stable Circular Orbit
(ISCO) of massive test particle. It is shown that STVG plays a crucial role in
energy extraction from a rotating black hole, with an energy efficiency of more
than according to the Penrose process. Furthermore, we have explored
the gravitational synchrotron radiation analogue produced by a massive particle
orbiting around a Kerr-MOG black hole. It has been shown that the intensity of
gravitational radiation from binary systems of stellar black holes (SBH) and
supermassive black holes (SMBH).Comment: 9 pages, 7 figure