Vacuum Energy and the Topology of the Universe

2011 ◽  
pp. 35-44 ◽  
Author(s):  
Manuel Asorey ◽  
Inés Cavero-Peláez ◽  
José M. Muãoz-Castaãeda
Keyword(s):  
Vacuum Energy ◽  
Topology Of The Universe ◽  
The Universe

Wormholes and large-scale topology of the Universe

1996 ◽  
Vol 111 (12) ◽  
pp. 1433-1438 ◽  
Author(s):  
Zhen-Qiang Tan ◽  
You-Gen Shen
Keyword(s):  
Large Scale ◽  
Topology Of The Universe ◽  
The Universe

scholarly journals On The Symmetry of The Universe

2020 ◽  
Author(s):  
Engel Roza
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Thermodynamic Equilibrium ◽  
Vacuum Energy ◽  
Quantum Mechanical ◽  
Baryonic Matter ◽  
Time Uncertainty ◽  
Matter Effect ◽  
Mechanical Interpretation ◽  
The Universe

It is shown that the Lambda component in the cosmological Lambda-CDM model can be conceived as vacuum energy, consisting of gravitational particles subject to Heisenberg’s energy-time uncertainty. These particles can be modelled as elementary polarisable Dirac-type dipoles (“darks”) in a fluidal space at thermodynamic equilibrium, with spins that are subject to the Bekenstein-Hawking entropy. Around the baryonic kernels, uniformly distributed in the universe, the spins are polarized, thereby invoking an increase of the effective gravitational strength of the kernels. It explains the dark matter effect to the extent that the numerical value of Milgrom’s acceleration constant can be assessed by theory. Non-polarized vacuum particles beyond the baryonic kernels compose the dark energy. The result is a quantum mechanical interpretation of gravity in terms of quantitatively established shares in baryonic matter, dark matter and dark energy, which correspond with the values of the Lambda-CDM model..

scholarly journals RADION POTENTIAL AND BRANE DYNAMICS

2001 ◽  
Vol 16 (24) ◽  
pp. 1583-1595 ◽  
Author(s):  
L. MERSINI
Keyword(s):  
Inflation Rate ◽  
Vacuum Energy ◽  
Density Perturbation ◽  
Scalar Fields ◽  
Fine Tuning ◽  
Late Time ◽  
Frw Universe ◽  
Strong Suppression ◽  
Dynamic Setting ◽  
The Universe

We examine the cosmology of Randall–Sundrum model in a dynamic setting where scalar fields are present in the bulk as well as the branes. This generates a mechanism similar to that of Goldberger–Wise for radion stabilization and the recovery of late-time cosmology features on the branes. Due to the induced radion dynamics, the inflating branes roll towards the minimum of the radion potential, thereby exiting inflation and reheating the universe. In the slow roll part of the potential, the TeV branes have maximum inflation rate and energy as their coupling to the radion and bulk modes have minimum suppression. Hence, when rolling down the steep end of the potential towards the stable point, the radion field (which appears as the inflaton of the effective 4-D theory in the branes) decays very fast and reheats the universe. This process results in a decrease of the brane's canonical vacuum energy, Λ4. However, at the minimum of the potential Λ4 is small but not necessarily zero and the fine-tuning issue remains. Density perturbation constraints introduce an upper bound on Λ4. Due to the large radion mass and strong suppression to the bulk modes, moduli problems and bulk reheating do not occur. The reheat temperature and a sufficient number of e-folding constraints for the brane-universe are also satisfied. The model therefore recovers the radiation dominated FRW universe.

Signature of Topology of the Universe

2018 ◽  
Vol 2 (01) ◽  
Author(s):  
Vipin Kumar Sharma
Keyword(s):  
General Relativity ◽  
Energy Density ◽  
Local Geometry ◽  
Microwave Background ◽  
Main Motivation ◽  
And Topology ◽  
The Standard Model ◽  
Topology Of The Universe ◽  
The Universe ◽  
Insight Into

The main motivation to write this article is to relate the cosmology and topology in order to gain some insight into the topological signatures of the Standard model of Universe. The theory of General Relativity as given by Einstein only describes the local geometry of space but not global, hence leaves the possibility to explore the topology of the space (simply- or multi-connected). By expressing the cosmological model in trms of energy density parameters, we attempt to understand the geometry of spacetime. This is followed by a discussion on the possibility to detect the signatures of topology of space imprinted on the Cosmic Microwave Background (CMB).

Topology of the Universe

1987 ◽  
pp. 461-475 ◽  
Author(s):  
L. Z. Fang ◽  
H. J. Mo
Keyword(s):  
Topology Of The Universe ◽  
The Universe

scholarly journals Do we come from a quantum anomaly?

2019 ◽  
Vol 28 (14) ◽  
pp. 1944002 ◽  
Author(s):  
Spyros Basilakos ◽  
Nick E. Mavromatos ◽  
Joan Solà Peracaula
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Energy Density ◽  
Hubble Parameter ◽  
Vacuum Energy ◽  
Vacuum Energy Density ◽  
Quantum Anomaly ◽  
Inflationary Phase ◽  
Axion Field ◽  
The Universe

We present a string-based picture of the cosmological evolution in which (CP-violating) gravitational anomalies acting during the inflationary phase of the universe cause the vacuum energy density to “run” with the effective Hubble parameter squared, [Formula: see text], thanks to the axion field of the bosonic string multiplet. This leads to baryogenesis through leptogenesis with massive right-handed neutrinos. The generation of chiral matter after inflation helps in cancelling the anomalies in the observable radiation- and matter-dominated eras. The present era inherits the same “running vacuum” structure triggered during the inflationary time by the axion field. The current dark energy is thus predicted to be mildly dynamical, and dark matter should be made of axions. Paraphrasing Carl Sagan [ https://www.goodreads.com/author/quotes/10538.Carl_Sagan .]: we are all anomalously made from starstuff.

scholarly journals Are there Ghost Images of the Coma Cluster at other Redshifts?

1999 ◽  
Vol 183 ◽  
pp. 263-263
Author(s):  
Boudewijn F. Roukema
Keyword(s):  
Fundamental Property ◽  
Infinite Volume ◽  
Coma Cluster ◽  
Negatively Curved ◽  
Image Position ◽  
Topology Of The Universe ◽  
The Universe ◽  
Ghost Images

The topology of the Universe is a fundamental property of our Universe according to Friedmann-Lemaître models[3, 9, 7], but has not yet been reliably measured. As pointed out by Sato[12], the Universe may be finite even though flat or negatively curved: infinite volume of a hypersurface.

A model of the universe with decaying vacuum energy

Pramana ◽  
1996 ◽  
Vol 47 (1) ◽  
pp. 41-55 ◽  
Author(s):  
A B Dussattar ◽  
R G Vishwakarma
Keyword(s):  
Vacuum Energy ◽  
The Universe

scholarly journals WHY THERE IS SOMETHING SO CLOSE TO NOTHING: TOWARDS A FUNDAMENTAL THEORY OF THE COSMOLOGICAL CONSTANT

2007 ◽  
Vol 22 (10) ◽  
pp. 1797-1818 ◽  
Author(s):  
VISHNU JEJJALA ◽  
DJORDJE MINIC
Keyword(s):  
Quantum Theory ◽  
String Theory ◽  
Cosmological Constant ◽  
Vacuum Energy ◽  
Uncertainty Relation ◽  
Space Time ◽  
Large Size ◽  
Minkowski Space Time ◽  
The Universe ◽  
Canonical Quantum

The cosmological constant problem is turned around to argue for a new foundational physics postulate underlying a consistent quantum theory of gravity and matter, such as string theory. This postulate is a quantum equivalence principle which demands a consistent gauging of the geometric structure of canonical quantum theory. We argue that string theory can be formulated to accommodate such a principle, and that in such a theory the observed cosmological constant is a fluctuation about a zero value. This fluctuation arises from an uncertainty relation involving the cosmological constant and the effective volume of space–time. The measured, small vacuum energy is dynamically tied to the large "size" of the universe, thus violating naive decoupling between small and large scales. The numerical value is related to the scale of cosmological supersymmetry breaking, supersymmetry being needed for a nonperturbative stability of local Minkowski space–time regions in the classical regime.

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