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Dzhunushaliev V.,Kyrgyz Russian Slavic University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Dzhunushaliev V.,University of Oldenburg | Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Folomeev V.,University of Oldenburg
General Relativity and Gravitation | Year: 2010

The possible process of creation/annihilation of traversable wormholes in the model with phantom (ghost) scalar field is described. It is shown that such process can be realized only for some special choice of a potential energy, in particular, for the Sine-Gordon potential. © 2010 Springer Science+Business Media, LLC.


Dzhunushaliev V.,KazNU | Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Makhmudov A.,Peoples' Friendship University of Russia | Urazalina A.,KazNU | And 4 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

In this work, we investigate localized and extended objects for gravitating, self-interacting phantom fields. The phantom fields come from two scalar fields with a "wrong-sign" (negative) kinetic energy term in the Lagrangian. This study covers several solutions supported by these phantom fields: phantom balls, traversable wormholes, phantom cosmic strings, and "phantom" domain walls. These four systems are solved numerically, and we try to draw out general, interesting features in each case. © 2016 American Physical Society.


Folomeev V.,University of Oldenburg | Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Singleton D.,California State University, Fresno
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

In this paper we investigate gravitationally bound, spherically symmetric equilibrium configurations consisting of ordinary (polytropic) matter nonminimally coupled to an external chameleon scalar field. We show that this system has static, regular, asymptotically flat general relativistic solutions. The properties of these spherical configurations, such as total mass, distribution of matter, and size, depend strongly on the surrounding scalar field. The mass is found in terms of the parameter σ, which is proportional to the central mass density of the ordinary matter. We perform a stability analysis of these spherical solutions and find an upper bound for σ where dynamical instability occurs. © 2012 American Physical Society.


Dzhunushaliev V.,Al-Farabi Kazakh National University | Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic
European Physical Journal C | Year: 2015

We consider the propagation of strong gravitational waves interacting with a nonperturbative vacuum of spinor fields. To described the latter, we suggest an approximate model. The corresponding Einstein equation has the form of the Schrödinger equation. Its gravitational-wave solution is analogous to the solution of the Schrödinger equation for an electron moving in a periodic potential. The general solution for the periodic gravitational waves is found. The analog of the Kronig–Penney model for gravitational waves is considered. It is shown that the suggested gravitational-wave model permits the existence of weak electric charge and current densities concomitant with the gravitational wave. Based on this observation, a possible experimental verification of the model is suggested. © 2015, The Author(s).


Dzhunushaliev V.,University of Oldenburg | Dzhunushaliev V.,Al-Farabi Kazakh National University | Dzhunushaliev V.,Kazakh National University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | And 5 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We consider rotating Lorentzian wormholes with a phantom field in five dimensions. These wormhole solutions possess equal angular momenta and thus represent cohomogeneity-1 configurations. For a given size of the throat, the angular momenta are bounded by the value of the corresponding extremal Myers-Perry black hole, which represents the limiting configuration. With increasing angular momenta the throat becomes increasingly deformed. At the same time, the violation of the null energy condition decreases to zero, as the limiting configuration is approached. Symmetric wormhole solutions satisfy a Smarr-like relation, which is analogous to the Smarr relation of extremal black holes. A stability analysis shows that the unstable mode of the static wormhole solutions vanishes when the angular momentum exceeds some critical value. © 2013 American Physical Society.


Dzhunushaliev V.,Kazakh National University | Dzhunushaliev V.,Eurasian University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Dzhunushaliev V.,University of Oldenburg | And 4 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We consider configurations consisting of a neutron star with a wormhole at the core. The wormhole is held open by a ghost scalar field with a quartic coupling. The neutron matter is described by a perfect fluid with a polytropic equation of state. We obtain static regular solutions for these systems. A stability analysis, however, shows that they are unstable with respect to linear perturbations. © 2013 American Physical Society.


Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Dzhunushaliev V.,Al-Farabi Kazakh National University | Dzhunushaliev V.,Eurasian University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Relativistic, spherically symmetric configurations consisting of a gravitating magnetized anisotropic fluid are studied. For such configurations, we obtain static equilibrium solutions with an axisymmetric, poloidal magnetic field produced by toroidal electric currents. The presence of such a field results in small deviations of the shape of the configuration from spherical symmetry. This in turn leads to the modification of an equation for the current and correspondingly to changes in the structure of the internal magnetic field for the systems supported by the anisotropic fluid, in contrast to the case of an isotropic fluid, where such deviations do not affect the magnetic field. © 2015 American Physical Society.


Dzhunushaliev V.,Al-Farabi Kazakh National University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Dzhunushaliev V.,University of Oldenburg | Folomeev V.,Al-Farabi Kazakh National University | And 3 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We consider neutron-star-plus-wormhole configurations supported by a massless ghost scalar field. The neutron fluid is modeled by an anisotropic equation of state. When the central energy density of the fluid is of comparable magnitude to the one of the scalar field, configurations with an equator at the center and a double throat arise. These double-throat wormholes can be either partially or completely filled by the neutron fluid. In the latter case, the passage of light - radiated by the neutron matter - through these wormholes is studied. A stability analysis indicates that all considered configurations are unstable with respect to linear perturbations, independent of whether the fluid is isotropic or anisotropic. © 2014 American Physical Society.


Aringazin A.,Eurasian University | Dzhunushaliev V.,University of Oldenburg | Dzhunushaliev V.,Al-Farabi Kazakh National University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | And 4 more authors.
Journal of Cosmology and Astroparticle Physics | Year: 2015

We consider mixed configurations consisting of a wormhole filled by a strongly magnetized isotropic or anisotropic neutron fluid. The nontrivial topology of the spacetime is allowed by the presence of exotic matter. By comparing these configurations with ordinary magnetized neutron stars, we clarify the question of how the presence of the nontrivial topology influences the magnetic field distribution inside the fluid. In the case of an anisotropic fluid, we find new solutions describing configurations, where the maximum of the fluid density is shifted from the center. A linear stability analysis shows that these mixed configurations are unstable. © 2015 IOP Publishing Ltd and Sissa Medialab srl.


Dzhunushaliev V.,Al-Farabi Kazakh National University | Dzhunushaliev V.,Eurasian University | Dzhunushaliev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic | Folomeev V.,Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic
European Physical Journal C | Year: 2014

The propagation of gravitational waves on the background of a nonperturbative vacuum of a spinor field is considered. It is shown that there are several distinctive features in comparison with the propagation of plane gravitational waves through empty space: there exists a fixed phase difference between the hyy,zz and hy,z components of the wave; the phase and group velocities of gravitational waves are not equal to the velocity of light; the group velocity is always less than the velocity of light; under some conditions the gravitational waves are either damped or absent; for given frequency, there exist two waves with different wave vectors. We also discuss the possibility of an experimental verification of the obtained effects as a tool to investigate nonperturbative quantum field theories. © 2014, The Author(s).

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