Prof.
Kirill Bronnikov
(VNIIMS)
03/10/2017, 08:00
For static, spherically symmetric space-times in general relativity (GR), a no-go theorem is proved: it excludes the existence of wormholes with flat and/or AdS asymptotic regions on both sides of the throat if the source matter is isotropic, i.e., the radial and tangential pressures coincide. Under a simple assumption on the behavior of the spherical radius $r(x)$, we obtain a number of ...
Prof.
Victor Berezin
(Institute for Nuclear Research of the Russian Academy of Sciences)
03/10/2017, 08:15
The spherically symmetric thin shells are the nearest generalizations of the point-like particles. Moreover, they serve as the simple source of the gravitational fields both in General Relativity and much more complex quadratic gravity theories. We are interested in the special and physically umportant case when all the quadratic in curvature tensor (in Riemann tensor) and its constructions...
Dr.
Arkadiy Popov
(Institute of Mathematics and Mechanics, Kazan Federal University)
03/10/2017, 08:30
The distinguished role of extremal horizons is beyond any doubts. It is sufficient to mention briefly such issues as black hole entropy, the scenarios of evaporation including the nature of remnants, etc. Meanwhile, although such object appear naturally on the pure classical level (the famous examples is the Reissner-Nordstrom black hole with the mass equal to charge), the question of their...
Mr.
Ivan Potashov
(Tver State University)
,
Dr.
Julia Tchemarina
(Tver State University)
03/10/2017, 08:45
A topological geon is the quotient manifold $M/Z_{2}$ where $M$ is a static spherically symmetric wormhole having the reflectional symmetry with respect to its throat. We classify the space of such asymptotically flat solutions of the Einstein-Klein-Gordon equations according to the form of the time-time metric function by using the quadrature formulas of the so-called inverse problem for...
Dr.
Sergei Bolokhov
(Peoples' Friendship University of Russia)
03/10/2017, 09:00
A multidimensional generalization of Melvin's solution (originally describing the gravitational field of a magnetic flux tube in four dimensions) is considered. Being defined in $D$-dimensional spacetime, the generalized solution is also related to an arbitrary simple Lie algebra $\cal G$ corresponding to some hidden symmetries of the master equations of the model. The gravitational model...
Prof.
Valery Stepanov
(Russian Federation)
03/10/2017, 09:15
In 1930, Reichenbach established the possibility of generalization of Einstein's definition of synchronizing spatially separated a couple of hours, introducing Reichenbach parameter that varies from zero to one, which defines one-way speed of light. A fundamental constant is the average speed of light back and forth. The independence of this observed value of the choice of inertial reference...
Dr.
Chitta Ranjan Das
(BLTP, JINR, Dubna, Russia)
03/10/2017, 09:30
In the present talk, we consider the existence of the two
degenerate universal vacua: a) the first Electroweak vacuum at
$v=246$ GeV - "true vacuum", and b) the second Planck scale "false
vacuum" at $v_2\sim 10^{18}$ GeV. In these vacua, we investigated
the different topological defects. The main aim of this paper is
an investigation of the hedgehog's configurations as defects of...
Dr.
M. Ayub Faridi
(University of the Punjab)
03/10/2017, 09:45
**We investigate the transmission and reflection coefficient and absorption and scattering cross section of spin 0,1,2 particles which are massless from black holes. Here orbiting scattering can be characterized of massless particles from Reissner-Nordstrom black hole at a critical angular momentum. We examine the effects upon reflection,transmission,scattering and absorption cross section due...
