Erratum: Two‐point functions and stress‐energy tensors of p‐forms in de Sitter and anti‐de Sitter spaces [J. Math. Phys. 32, 2828 (1991)]

1992 ◽  
Vol 33 (5) ◽  
pp. 1932-1932 ◽  
Author(s):  
A. Folacci
Keyword(s):  
De Sitter ◽  
Stress Energy ◽  
Math Phys

scholarly journals Cosmological model favored by the holographic principle

2016 ◽  
Vol 41 ◽  
pp. 1660127
Author(s):  
Irina Dymnikova ◽  
Anna Dobosz ◽  
Bożena Sołtysek
Keyword(s):  
Cosmological Model ◽  
Cosmological Constant ◽  
Space Time ◽  
Holographic Principle ◽  
Einstein Equations ◽  
Energy Tensor ◽  
De Sitter ◽  
Quantum Evaporation ◽  
Stress Energy ◽  
De Sitter Vacua

We present a regular spherically symmetric cosmological model of the Lemaitre class distinguished by the holographic principle as the thermodynamically stable end-point of quantum evaporation of the cosmological horizon. A source term in the Einstein equations connects smoothly two de Sitter vacua with different values of cosmological constant and corresponds to anisotropic vacuum dark fluid defined by symmetry of its stress-energy tensor which is invariant under the radial boosts. Global structure of space-time is the same as for the de Sitter space-time. Cosmological evolution goes from a big initial value of the cosmological constant towards its presently observed value.

scholarly journals Schwarzschild-de Sitter and Anti-de Sitter Thin-Shell Wormholes and Their Stability

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
M. Sharif ◽  
Saadia Mumtaz
Keyword(s):  
Thin Shell ◽  
Chaplygin Gas ◽  
Exotic Matter ◽  
Energy Conditions ◽  
Energy Tensor ◽  
De Sitter ◽  
Stress Energy ◽  
Linear Perturbations ◽  
Unstable Solutions ◽  
Thin Shell Wormholes

This paper is devoted to construct Schwarzschild-de Sitter and anti-de Sitter thin-shell wormholes by employing Visser’s cut and paste technique. The Darmois-Israel formalism is adopted to formulate the surface stresses of the shell. We analyze null and weak energy conditions as well as attractive and repulsive characteristics of thin-shell wormholes. We also explore stable and unstable solutions against linear perturbations by taking two different Chaplygin gas models for exotic matter. It is concluded that the stress-energy tensor components violate the null and weak energy conditions indicating the existence of exotic matter at the wormhole throat. Finally, we find unstable and stable configurations for the constructed thin-shell wormholes.

scholarly journals QUANTUM KALB–RAMOND FIELD IN D-DIMENSIONAL DE SITTER SPACE–TIMES

2013 ◽  
Vol 28 (05n06) ◽  
pp. 1350011
Author(s):  
G. ALENCAR ◽  
I. GUEDES ◽  
R. R. LANDIM ◽  
R. N. COSTA FILHO
Keyword(s):  
Exact Solution ◽  
Wave Function ◽  
Quantum Theory ◽  
De Sitter Space ◽  
Equation Of Motion ◽  
Time Dependent ◽  
De Sitter ◽  
Sitter Background ◽  
Dynamic Invariant ◽  
Math Phys

In this work, we investigate the quantum theory of the Kalb–Ramond fields propagating in D-dimensional de Sitter space–times using the dynamic invariant method developed by Lewis and Riesenfeld [J. Math. Phys.10, 1458 (1969)] to obtain the solution of the time-dependent Schrödinger equation. The wave function is written in terms of a c-number quantity satisfying the Milne–Pinney equation, whose solution can be expressed in terms of two independent solutions of the respective equation of motion. We obtain the exact solution for the quantum Kalb–Ramond field in the de Sitter background and discuss its relation with the Cremmer–Scherk–Kalb–Ramond model.

scholarly journals The Damped Harmonic Oscillator at the Classical Limit of the Snyder-de Sitter Space

2021 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
Lat´evi M. Lawson ◽  
Ibrahim Nonkan´e ◽  
Komi Sodoga
Keyword(s):  
Harmonic Oscillator ◽  
Classical Limit ◽  
Minimal Length ◽  
Poisson Brackets ◽  
Canonical Transformations ◽  
Trigonometric Functions ◽  
De Sitter ◽  
One Dimensional ◽  
Damped Harmonic Oscillator ◽  
Math Phys

Valtancoli in his paper entitled (P. Valtancoli, Canonical transformations and minimal length, J. Math. Phys. 56, 122107 2015) has shown how the deformation of the canonical transformations can be made compatible with the deformed Poisson brackets. Based on this work and through an appropriate canonical transformation, we solve the problem of one dimensional (1D) damped harmonic oscillator at the classical limit of the Snyder-de Sitter (SdS) space. We show that the equations of the motion can be described by trigonometric functions with frequency and period depending on the deformed and the damped parameters. We eventually discuss the influences of these parameters on the motion of the system.

scholarly journals Constructions of f(R,G,𝒯) gravity from some expansions of the Universe

2020 ◽  
Vol 35 (31) ◽  
pp. 2050203
Author(s):  
Ujjal Debnath
Keyword(s):  
Energy Conditions ◽  
Energy Tensor ◽  
De Sitter ◽  
Field Equations ◽  
Least Action Principle ◽  
Future Singularity ◽  
Least Action ◽  
The Least Action Principle ◽  
Modified Gravity Theory ◽  
Stress Energy

Here we propose the extended modified gravity theory named [Formula: see text] gravity where [Formula: see text] is the Ricci scalar, [Formula: see text] is the Gauss–Bonnet invariant, and [Formula: see text] is the trace of the stress-energy tensor. We derive the gravitational field equations in [Formula: see text] gravity by taking the least action principle. Next we construct the [Formula: see text] in terms of [Formula: see text], [Formula: see text] and [Formula: see text] in de Sitter as well as power-law expansion. We also construct [Formula: see text] if the expansion follows the finite-time future singularity (big rip singularity). We investigate the energy conditions in this modified theory of gravity and examine the validity of all energy conditions.

Stability of ABG thin-shell around a traversable wormhole

2021 ◽  
pp. 2150044
Author(s):  
M. Sharif ◽  
Komal Ashraf
Keyword(s):  
Thin Shell ◽  
Shape Function ◽  
Energy Conditions ◽  
Energy Tensor ◽  
De Sitter ◽  
Stress Energy Tensor ◽  
Regular Black Hole ◽  
Traversable Wormhole ◽  
Stress Energy ◽  
Barotropic Equation

This paper investigates stability of thin-shell developed from the matching of interior traversable wormhole with exterior Ayon–Beato–Garcia–de Sitter regular black hole through cut and paste approach. We employ Israel formalism and Lanczos equations to obtain the components of surface stress-energy tensor at thin-shell. These surface stresses violate null and weak energy conditions that suggest the presence of exotic matter at thin-shell. The surface pressure explains collapse as well as expanding behavior of the developed geometry. We explore stability of the constructed thin-shell through both perturbations along shell radius as well as barotropic equation of state for three appropriate values of the shape function [Formula: see text]. It is concluded that stability of thin-shell depends on the shape function, charge and cosmological constant.

scholarly journals Quasi-normal modes for Dirac fields in the Kerr–Newman–de Sitter black holes

2018 ◽  
Vol 16 (04) ◽  
pp. 449-524
Author(s):  
Alexei Iantchenko
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Zeeman Effect ◽  
Normal Modes ◽  
Outer Region ◽  
Dirac Field ◽  
Commun Math Phys ◽  
De Sitter ◽  
Dirac Fields ◽  
Math Phys

We provide the full asymptotic description of the quasi-normal modes (resonances) in any strip of fixed width for Dirac fields in slowly rotating Kerr–Newman–de Sitter black holes. The resonances split in a way similar to the Zeeman effect. The method is based on the extension to Dirac operators of techniques applied by Dyatlov in [Quasi-normal modes and exponential energy decay for the Kerr–de Sitter black hole, Commun. Math. Phys. 306(1) (2011) 119–163; Asymptotic distribution of quasi-normal modes for Kerr–de Sitter black holes, Ann. Henri Poincaré 13(5) (2012) 1101–1166] to the (uncharged) Kerr–de Sitter black holes. We show that the mass of the Dirac field does not have an effect on the two leading terms in the expansions of resonances. We give an expansion of the solution of the evolution equation for the Dirac fields in the outer region of the slowly rotating Kerr–Newman–de Sitter black hole which implies the exponential decay of the local energy. Moreover, using the [Formula: see text]-normal hyperbolicity of the trapped set and applying the techniques from [Asymptotics of linear waves and resonances with applications to black holes, Commun. Math. Phys. 335 (2015) 1445–1485; Resonance projectors and asymptotics for [Formula: see text]-normally hyperbolic trapped sets, J. Amer. Math. Soc. 28 (2015) 311–381], we give location of the resonance free band and the Weyl-type formula for the resonances in the band near the real axis.

Dark ingredients in one drop

Open Physics ◽  
2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov
Keyword(s):  
Cosmological Term ◽  
Energy Tensor ◽  
De Sitter ◽  
Stress Energy Tensor ◽  
Dark Fluid ◽  
Spatially Inhomogeneous ◽  
Stress Energy ◽  
Gravitational Vacuum ◽  
De Sitter Vacuum ◽  
Unified Description

AbstractA unified description of dark ingredients is realized by a vacuum dark fluid defined by symmetry of its stress-energy tensor and allowed by General Relativity. The symmetry is reduced compared with the maximally symmetric de Sitter vacuum, which makes vacuum dark fluid essentially anisotropic and allows its density and pressure to evolve. It represents distributed vacuum dark energy by a time-evolving and spatially inhomogeneous cosmological term, and vacuum dark matter by gravitational vacuum solitons which are regular gravitationally bound structures without horizons (dark particles or dark stars), with the de Sitter centre (Λδki) in de Sitter space (λδki).

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