Corpus ID: 119226113

Negative Energy Cosmology and the Cosmological Constant

@article{Prokopec2011NegativeEC,
  title={Negative Energy Cosmology and the Cosmological Constant},
  author={Tomislav Prokopec},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
  year={2011}
}
  • T. Prokopec
  • Published 30 April 2011
  • Physics
  • arXiv: Cosmology and Nongalactic Astrophysics
It is well known that string theories naturally compactify on anti-de Sitter spaces, and yet cosmological observations show no evidence of a negative cosmological constant in the early Universe's evolution. In this letter we present two simple nonlocal modifications of the standard Friedmann cosmology that can lead to observationally viable cosmologies with an initial (negative) cosmological constant. The nonlocal operators we include are toy models for the quantum cosmological backreaction. In… Expand

Figures from this paper

Stochastic dark energy from inflationary quantum fluctuations
We study the quantum backreaction from inflationary fluctuations of a very light, non-minimally coupled spectator scalar and show that it is a viable candidate for dark energy. The problem is solvedExpand
A unifying theory of dark energy and dark matter: Negative masses and matter creation within a modified ΛCDM framework
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationallyExpand
A stable flat universe with variable cosmological constant in f(R, T) gravity
In this paper, a general FRW cosmological model has been constructed in f(R,T) gravity reconstruction with variable cosmological constant. A number of solutions to the field equations has beenExpand
A Proposal for a Unifying Theory of Dark Energy and Dark Matter
Dark energy and Dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationallyExpand
A cyclic universe with varying cosmological constant in f(R, T) gravity
A new kind of evolution for cyclic models in which the Hubble parameter oscillates and remains positive has been explored in a specific f(R, T) gravity reconstruction. A singularity-free cyclicExpand
De Sitter universe in nonlocal gravity
A nonlocal gravity model, which does not assume the existence of a new dimensional parameter in the action and includes a function $f(\Box^{-1} R)$, with $\Box$ the d'Alembertian operator, isExpand
Transition from decelerating to accelerating universe with quadratic equation of state in f(R,T) gravity
ABSTRACT In this paper, we have constructed a flat Friedmann-Robertson-Walker (FRW) cosmological model in gravity. The solution of Friedmann equations has been obtained assuming the quadraticExpand
Spontaneous Symmetry Breaking in the Early Universe with a Negative Temperature and a Broken Lorentz Symmetry
In this paper we show that, in the early universe, higher order curvature corrections induce spontaneous symmetry breaking with negative temperature and broken Lorentz symmetry when the gravitationalExpand
Cosmology with scalar–Euler form coupling
A coupling between the spacetime geometry and a scalar field involving the Euler 4-form can have important consequences in General Relativity. The coupling is a four-dimensional version of theExpand
A soliton and a black hole are in Gauss-Bonnet gravity: Who wins?
We study here the phase-transitional evolution between the Eguchi-Hanson soliton, the orbifolded Schwarzschild Anti de-Sitter black hole, and orbifolded thermal Anti de-Sitter space in Gauss-BonnetExpand
...
1
2
...

References

SHOWING 1-10 OF 10 REFERENCES
A Solution to the cosmological constant problem
We argue that, when coupled to Einstein's theory of gravity, the Yukawa theory may solve the cosmological constant problem in the following sense: The radiative corrections of fermions generate anExpand
Phenomenological model for the early universe
We consider the description of cosmological dynamics from the onset of inflation by a perfect fluid whose parameters must be consistent with the strength of the enhanced quantum loop effects that canExpand
Primordial density perturbations and reheating from gravity
We consider the presence and evolution of primordial density perturbations in a cosmological model based on a simple ansatz which captures--by providing a set of effective gravitational fieldExpand
Generating the curvature perturbation without an inflaton
We present a mechanism for the origin of the large-scale curvature perturbation in our Universe by the late decay of a massive scalar field, the curvaton. The curvaton is light during a period ofExpand
A simplified quantum gravitational model of inflation
Inflationary quantum gravity simplifies drastically in the leading logarithm approximation. We show that the only counterterm which contributes in this limit is the 1-loop renormalization of theExpand
Towards inflation in string theory
We investigate the embedding of brane inflation into stable compactifications of string theory. At first sight a warped compactification geometry seems to produce a naturally flat inflaton potential,Expand
Adiabatic CMB perturbations in pre - big bang string cosmology
Abstract We consider the pre-Big-Bang scenario with a massive axion field which starts to dominate energy density when oscillating in an instanton-induced potential and subsequently reheats theExpand
De Sitter vacua in string theory
We outline the construction of metastable de Sitter vacua of type IIB string theory. Our starting point is highly warped IIB compactifications with nontrivial NS and RR three-form fluxes. ByExpand
Nonlocal cosmology.
TLDR
Nonlocally modified models of gravity, inspired by quantum loop corrections, are explored, as a mechanism for explaining current cosmic acceleration, and their solar system effects are safely negligible, and they may even prove useful to the black hole information problem. Expand
The Inflationary Universe