scholarly journals Dark Matter Candidates with Dark Energy Interiors Determined by Energy Conditions

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 662 ◽  
Author(s):  
Irina Dymnikova
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Energy Condition ◽  
Phantom Energy ◽  
Weak Energy Condition ◽  
Energy Conditions ◽  
De Sitter ◽  
Dynamical Equations ◽  
De Sitter Vacuum ◽  
Observational Signature

We outline the basic properties of regular black holes, their remnants and self-gravitating solitons G-lumps with the de Sitter and phantom interiors, which can be considered as heavy dark matter (DM) candidates generically related to a dark energy (DE). They are specified by the condition T t t = T r r and described by regular solutions of the Kerr-Shild class. Solutions for spinning objects can be obtained from spherical solutions by the Newman-Janis algorithm. Basic feature of all spinning objects is the existence of the equatorial de Sitter vacuum disk in their deep interiors. Energy conditions distinguish two types of their interiors, preserving or violating the weak energy condition dependently on violation or satisfaction of the energy dominance condition for original spherical solutions. For the 2-nd type the weak energy condition is violated and the interior contains the phantom energy confined by an additional de Sitter vacuum surface. For spinning solitons G-lumps a phantom energy is not screened by horizons and influences their observational signatures, providing a source of information about the scale and properties of a phantom energy. Regular BH remnants and G-lumps can form graviatoms binding electrically charged particles. Their observational signature is the electromagnetic radiation with the frequencies depending on the energy scale of the interior de Sitter vacuum within the range available for observations. A nontrivial observational signature of all DM candidates with de Sitter interiors predicted by analysis of dynamical equations is the induced proton decay in an underground detector like IceCUBE, due to non-conservation of baryon and lepton numbers in their GUT scale false vacuum interiors.

scholarly journals Graviatoms with de Sitter Interior

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Irina Dymnikova ◽  
Michael Fil’chenkov
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Dark Energy ◽  
Charged Particle ◽  
Energy Spectrum ◽  
Primordial Black Hole ◽  
De Sitter ◽  
Fundamental Symmetry ◽  
Gravitational Vacuum ◽  
De Sitter Vacuum

We present a graviatom with de Sitter interior as a new candidate to atomic dark matter generically related to a vacuum dark energy through its de Sitter vacuum interior. It is a gravitationally bound quantum system consisting of a nucleus represented by a regular primordial black hole (RPBH), its remnant or gravitational vacuum soliton G-lump, and a charged particle. We estimate probability of formation of RPBHs and G-lumps in the early Universe and evaluate energy spectrum and electromagnetic radiation of graviatom which can in principle bear information about a fundamental symmetry scale responsible for de Sitter interior and serve as its observational signatures.

Unification of dark energy and dark matter based on the Petrov classification and space-time symmetry

2016 ◽  
Vol 31 (02n03) ◽  
pp. 1641005 ◽  
Author(s):  
Irina Dymnikova
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Space Time ◽  
Cosmological Term ◽  
De Sitter ◽  
Dark Fluid ◽  
Time Symmetry ◽  
Stress Energy ◽  
Petrov Classification ◽  
De Sitter Vacuum

The Petrov classification of stress-energy tensors provides a model-independent definition of a vacuum by the algebraic structure of its stress-energy tensor and implies the existence of vacua whose symmetry is reduced as compared with the maximally symmetric de Sitter vacuum associated with the Einstein cosmological term. This allows to describe a vacuum in general setting by dynamical vacuum dark fluid, presented by a variable cosmological term with the reduced symmetry which makes vacuum dark fluid essentially anisotropic and allows it to be evolving and clustering. The relevant regular solutions to the Einstein equations describe regular cosmological models with time-evolving and spatially inhomogeneous vacuum dark energy, and compact vacuum objects generically related to a dark energy through the de Sitter vacuum interior: regular black holes, their remnants and self-gravitating vacuum solitons — which can be responsible for observational effects typically related to a dark matter. The mass of objects with de Sitter interior is generically related to vacuum dark energy and to breaking of space-time symmetry.

scholarly journals Regular rotating electrically charged structures in nonlinear electrodynamics minimally coupled to gravity

2016 ◽  
Vol 41 ◽  
pp. 1660120 ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition ◽  
Nonlinear Electrodynamics ◽  
Perfect Conductor ◽  
Spherically Symmetric ◽  
Axially Symmetric ◽  
De Sitter ◽  
Superconducting Current ◽  
De Sitter Vacuum ◽  
Electrically Charged

In nonlinear electrodynamics minimally coupled to gravity, regular spherically symmetric electrically charged solutions satisfy the weak energy condition and have obligatory de Sitter center. By the Gürses-Gürsey algorithm they are transformed to regular axially symmetric solutions asymptotically Kerr-Newman for a distant observer. Rotation transforms de Sitter center into de Sitter equatorial disk embedded as a bridge into a de Sitter vacuum surface. The de Sitter surfaces satisfy [Formula: see text] and have properties of a perfect conductor and ideal diamagnetic. The Kerr ring singularity is replaced with the superconducting current which serves as a non-dissipative electromagnetic source of the asymptotically Kerr-Newman geometry. Violation of the weak energy condition is prevented by the basic requirement of electrodynamics of continued media.

Supergravity as the Dark Side of the Universe

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040038
Author(s):  
Sergei V. Ketov
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Dark Matter Particle ◽  
Dark Side ◽  
De Sitter ◽  
Positive Cosmological Constant ◽  
Starobinsky Model ◽  
Cosmological Inflation ◽  
De Sitter Vacuum ◽  
The Universe

The Dark Side of the Universe, which includes the cosmological inflation in the early Universe, the current dark energy and dark matter, can be theoretically described by supergravity, though it is non-trivial. We recall the arguments pro and contra supersymmetry and supergravity, and define the viable supergravity models describing the Dark Side of the Universe in agreement with all current observations. Our approach to inflation is based on the Starobinsky model, the dark energy is identified with the positive cosmological constant (de Sitter vacuum), and the dark matter particle is given by the lightest superparticle identified with the supermassive gravitino. The key role is played by spontaneous supersymmetry breaking.

scholarly journals Traversable wormholes in Einsteinian cubic gravity

2019 ◽  
Vol 35 (06) ◽  
pp. 2050017 ◽  
Author(s):  
Mohammad Reza Mehdizadeh ◽  
Amir Hadi Ziaie
Keyword(s):  
Equation Of State ◽  
Gravitational Lensing ◽  
Energy Condition ◽  
Higher Order ◽  
Energy Conditions ◽  
Geodesic Motion ◽  
De Sitter ◽  
Asymptotically Flat ◽  
Traversable Wormholes ◽  
Standard Energy

In this work, we investigate wormhole configurations described by a constant redshift function in Einstein-Cubic gravity ( ECG ). We derive analytical wormhole geometries by assuming a particular equation of state ( EoS ) and investigate the possibility that these solutions satisfy the standard energy conditions. We introduce exact asymptotically flat and anti-de Sitter (AdS) spacetimes that admit traversable wormholes. These solutions are obtained by imposing suitable values for the parameters of the theory so that the resulted geometries satisfy the weak energy condition ( WEC ) in the vicinity of the throat, due to the presence of higher-order curvature terms. Moreover, we find that AdS solutions satisfy the WEC throughout the spacetime. A description of the geodesic motion of time-like and null particles is presented for the obtained wormhole solutions. Also, using gravitational lensing effects, observational features of the wormhole structure are discussed.

scholarly journals KINKS, ENERGY CONDITIONS AND CLOSED TIMELIKE CURVES

2000 ◽  
Vol 09 (05) ◽  
pp. 531-541 ◽  
Author(s):  
PEDRO F. GONZÁLEZ-DÍAZ
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition ◽  
Energy Conditions ◽  
Closed Timelike Curves ◽  
Causality Violation ◽  
Incoherent Radiation ◽  
Cylindrically Symmetric ◽  
Cylindrically Symmetric Spacetime ◽  
Geodesically Complete ◽  
Symmetric Spacetime

A link between the possibility of extending a geodesically incomplete kinked spacetime to a spacetime which is geodesically complete and the energy conditions is discussed for the case of a cylindrically-symmetric spacetime kink. It is concluded that neither the strong nor the weak energy condition can be satisfied in the four-dimensional example, though the latter condition may survive on the transversal sections of such a spacetime. It is also shown that the matter which propagates quantum-mechanically in a kinked spacetime can always be trapped by closed timelike curves, but signaling connections between that matter and any possible observer can only be made of totally incoherent radiation, so preventing observation of causality violation.

scholarly journals NONLINEAR EQUATION OF STATE, COSMIC ACCELERATION AND DECELERATION DURING PHANTOM DOMINANCE

2009 ◽  
Vol 18 (02) ◽  
pp. 329-345 ◽  
Author(s):  
S. K. SRIVASTAVA ◽  
J. DUTTA
Keyword(s):  
Equation Of State ◽  
Nonlinear Equation ◽  
Energy Condition ◽  
Phantom Energy ◽  
Weak Energy Condition ◽  
Cosmic Acceleration ◽  
Strong Energy Condition ◽  
Strong Energy ◽  
Acceleration And Deceleration ◽  
The Universe

In this paper, the RS-II model of brane gravity is considered for the phantom universe using a nonlinear equation of state. Phantom fluid is known to violate the weak energy condition. It is found that this characteristic of phantom energy is affected drastically by the negative brane tension λ of the RS-II model. It is interesting to see that up to a certain value of energy density ρ satisfying ρ/λ < 1, the weak energy condition is violated and the universe superaccelerates. But, as ρ increases more, only the strong energy condition is violated and the universe accelerates. When 1 < ρ/λ < 2, even the strong energy condition is not violated and the universe decelerates. Expansion of the universe stops when ρ = 2 λ. This is contrary to earlier results of the phantom universe exhibiting acceleration only.

scholarly journals Dynamics of Electromagnetic Fields and Structure of Regular Rotating Electrically Charged Black Holes and Solitons in Nonlinear Electrodynamics Minimally Coupled to Gravity

Universe ◽  
2019 ◽  
Vol 5 (10) ◽  
pp. 205 ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov
Keyword(s):  
Black Holes ◽  
Electromagnetic Fields ◽  
Nonlinear Electrodynamics ◽  
Axially Symmetric ◽  
De Sitter ◽  
Dynamical Equations ◽  
Naked Singularities ◽  
Charged Black Holes ◽  
De Sitter Vacuum ◽  
Electrically Charged

We study the dynamics of electromagnetic fields of regular rotating electrically charged black holes and solitons replacing naked singularities in nonlinear electrodynamics minimally coupled to gravity (NED-GR). They are related by electromagnetic and gravitational interactions and described by the axially symmetric NED-GR solutions asymptotically Kerr-Newman for a distant observer. Geometry is described by the metrics of the Kerr-Schild class specified by T t t = T r r ( p r = − ρ ) in the co-rotating frame. All regular axially symmetric solutions obtained from spherical solutions with the Newman-Janis algorithm belong to this class. The basic generic feature of all regular objects of this class, both electrically charged and electrically neutral, is the existence of two kinds of de Sitter vacuum interiors. We analyze the regular solutions to dynamical equations for electromagnetic fields and show which kind of a regular interior is favored by electromagnetic dynamics for NED-GR objects.

WIGGLY COSMIC STRINGS ACCRETE DARK ENERGY

2006 ◽  
Vol 15 (04) ◽  
pp. 603-613 ◽  
Author(s):  
PEDRO F. GONZÁLEZ-DÍAZ ◽  
JOSÉ A. JIMÉNEZ MADRID
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Cosmic Strings ◽  
Energy Condition ◽  
Phantom Energy ◽  
Dominant Energy Condition ◽  
Final State ◽  
Cylindrically Symmetric ◽  
Energy Models ◽  
Maximum Value

This paper deals with a study of the cylindrically symmetric accretion of dark energy with equation of state p = wρ onto wiggly straight cosmic strings, interpreting that the accreted energy only contributes the extent of the wiggliness, but consistently leaves invariant the unperturbed line density μ0. We have obtained that when w > -1, the perturbed linear energy density in the string core gradually increases tending to a finite maximum value as time increases, for all considered dark energy models. Where the dominant energy condition is violated, all such models predict a steady decreasing of the perturbed linear energy density μ of the cosmic strings as phantom energy is being accreted. The final state of the string after such an accretion process is a wiggleless defect. It is argued however, that if accreation of phantom energy would proceed by successive quantum steps, then the defect would continue losing perturbed linear energy density beyond μ0, until a minimum nonzero value which can be smaller than that corresponding to the unperturbed string.

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