scholarly journals Time-dependent compactification to de Sitter space: a no-go theorem

2019 ◽  
Vol 2019 (6) ◽  
Author(s):  
J. G. Russo ◽  
P. K. Townsend
Keyword(s):  
De Sitter Space ◽  
Time Dependent ◽  
De Sitter

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 SPONTANEOUS DECAY OF THE EFFECTIVE COSMOLOGICAL CONSTANT

1998 ◽  
Vol 13 (07) ◽  
pp. 571-580 ◽  
Author(s):  
MURAT ÖZER ◽  
M. O. TAHA
Keyword(s):  
Cosmological Constant ◽  
De Sitter Space ◽  
Space Time ◽  
Time Dependent ◽  
Spontaneous Decay ◽  
Quantum Fields ◽  
De Sitter ◽  
Initial Value ◽  
Effective Time ◽  
Effective Cosmological Constant

We discuss the notion that quantum fields may induce an effective time-dependent cosmological constant which decays from a large initial value. It is shown that such cosmological models are viable in a non-de Sitter space–time.

scholarly journals Cosmological anti–de Sitter space-times and time-dependent AdS/CFT correspondence

2004 ◽  
Vol 69 (2) ◽  
Author(s):  
Mirjam Cvetič ◽  
Shin’ichi Nojiri ◽  
Sergei D. Odintsov
Keyword(s):  
De Sitter Space ◽  
Time Dependent ◽  
De Sitter

scholarly journals Time dependent couplings as observables in de Sitter space

2014 ◽  
Vol 29 (08) ◽  
pp. 1430016 ◽  
Author(s):  
Hiroyuki Kitamoto ◽  
Yoshihisa Kitazawa
Keyword(s):  
Physical Mechanism ◽  
Quantum Effect ◽  
De Sitter Space ◽  
Time Dependent ◽  
General Covariance ◽  
De Sitter ◽  
Scale Invariant ◽  
Logarithmic Corrections ◽  
Slow Roll ◽  
The One

We summarize and expand our investigations concerning the soft graviton effects on microscopic matter dynamics in de Sitter space. The physical couplings receive IR logarithmic corrections which are sensitive to the IR cutoff at the one-loop level. The scale invariant spectrum in the gravitational propagator at the super-horizon scale is the source of the de Sitter symmetry breaking. The quartic scalar, Yukawa and gauge couplings become time dependent and diminish with time. In contrast, the Newton's constant increases with time. We clarify the physical mechanism behind these effects in terms of the conformal mode dynamics in analogy with 2d quantum gravity. We show that they are the inevitable consequence of the general covariance and lead to gauge invariant predictions. We construct a simple model in which the cosmological constant is self-tuned to vanish due to UV–IR mixing effect. We also discuss phenomenological implications such as decaying Dark Energy and SUSY breaking at the inflation era. The quantum effect alters the classical slow roll picture in general, if the tensor-to-scalar ratio r is as small as 0.01.

scholarly journals Gravitational turbulent instability of anti-de Sitter space

2012 ◽  
Vol 29 (19) ◽  
pp. 194002 ◽  
Author(s):  
Óscar J C Dias ◽  
Gary T Horowitz ◽  
Jorge E Santos
Keyword(s):  
De Sitter Space ◽  
De Sitter

scholarly journals Geometries with mismatched branes

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Andreas Karch ◽  
Lisa Randall
Keyword(s):  
Boundary Conditions ◽  
Effective Action ◽  
Cosmological Models ◽  
Time Dependent ◽  
De Sitter ◽  
Stabilization Mechanism ◽  
New Class ◽  
Vacuum Solutions ◽  
Single Coordinate

Abstract We study Randall-Sundrum two brane setups with mismatched brane tensions. For the vacuum solutions, boundary conditions demand that the induced metric on each of the branes is either de Sitter, Anti-de Sitter, or Minkowski. For incompatible boundary conditions, the bulk metric is necessarily time-dependent. This introduces a new class of time-dependent solutions with the potential to address cosmological issues and provide alternatives to conventional inflationary (or contracting) scenarios. We take a first step in this paper toward such solutions. One important finding is that the resulting solutions can be very succinctly described in terms of an effective action involving only the induced metric on either one of the branes and the radion field. But the full geometry cannot necessarily be simply described with a single coordinate patch. We concentrate here on the time- dependent solutions but argue that supplemented with a brane stabilization mechanism one can potentially construct interesting cosmological models this way. This is true both with and without a brane stabilization mechanism.

scholarly journals Open quantum entanglement: a study of two atomic system in static patch of de Sitter space

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Samim Akhtar ◽  
Sayantan Choudhury ◽  
Satyaki Chowdhury ◽  
Debopam Goswami ◽  
Sudhakar Panda ◽  
...  
Keyword(s):  
Scalar Field ◽  
Density Matrix ◽  
Master Equation ◽  
Quantum Entanglement ◽  
De Sitter Space ◽  
Thermal Bath ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Open Quantum ◽  
Non Locality

Abstract In this work, our prime objective is to study non-locality and long range effect of two body correlation using quantum entanglement from various information theoretic measure in the static patch of de Sitter space using a two body Open Quantum System (OQS). The OQS is described by a system of two entangled atoms, surrounded by a thermal bath, which is modelled by a massless probe scalar field. Firstly, we partially trace over the bath field and construct the Gorini Kossakowski Sudarshan Lindblad (GSKL) master equation, which describes the time evolution of the reduced subsystem density matrix. This GSKL master equation is characterized by two components, these are-Spin chain interaction Hamiltonian and the Lindbladian. To fix the form of both of them, we compute the Wightman functions for probe massless scalar field. Using this result alongwith the large time equilibrium behaviour we obtain the analytical solution for reduced density matrix. Further using this solution we evaluate various entanglement measures, namely Von-Neumann entropy, R$$e'$$e′nyi entropy, logarithmic negativity, entanglement of formation, concurrence and quantum discord for the two atomic subsystem on the static patch of De-Sitter space. Finally, we have studied violation of Bell-CHSH inequality, which is the key ingredient to study non-locality in primordial cosmology.

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