scholarly journals A MODEL OF A SIMPLE, BARYON-DOMINATED UNIVERSE THAT EXPANDS AT AN EVER-INCREASING RATE WITHOUT RELYING ON VACUUM ENERGY (Λ)

2011 ◽  
Vol 26 (33) ◽  
pp. 2501-2521
Author(s):  
GREG P. PROPER
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Vacuum Energy ◽  
Absolute Magnitude ◽  
Short Paper ◽  
Modern Cosmology ◽  
Spacetime Metric ◽  
The Universe ◽  
Prevailing View

The prevailing view in modern cosmology is that the universe is comprised of immense quantities of exotic materials (i.e. Dark Matter and Dark Energy) that have yet to be positively identified. However, there is also a small group of scientists who believe that the answer to this dilemma is to be found in the modification of gravity (i.e. General Relativity). This short paper states that if we make the bold assumption that all objects/observers are comprised of sets of spacetime coordinates that change (albeit slowly) as the universe ages, then three puzzles that currently confront cosmologists, astronomers and astrophysicists can easily be answered using relatively simple calculations. The condition necessary to explore this possibility can be obtained if one postulates that relativistic gravitational potential lessens (in absolute magnitude) everywhere as the universe ages (n). That is, the spacetime metric gμν(x)→gμν(x, n). If gravity behaves in this manner, then it can be shown that it is the causitive agent of indeterminism in nature.

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 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.

Dark Matter

2021 ◽  
pp. 66-78
Author(s):  
Gianfranco Bertone
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Gravitational Waves ◽  
Expansion Rate ◽  
The Earth ◽  
Modern Cosmology ◽  
Large Effort ◽  
The Universe

I introduce here the problem of dark energy, a substance that appears to be pushing the Universe to expand ever faster and discuss the large effort currently in place to understand its origin. I describe the surprising recent discovery of a widening crack in the cathedral of modern cosmology arising from the measurement of the expansion rate of the Universe. And I argue that gravitational waves observations can help us to either repair that crack, or to bring down that magnificent building, in case it turns out to be fatally flawed. Before all women and all men. Before animals, plants, archaeans, bacteria. Before the Earth was formed and the stars were lit. Before everything we know, the Universe was immersed in an amorphous and oblivious darkness.

scholarly journals Fundamental scalar fields and the dark side of the universe

2015 ◽  
Vol 24 (12) ◽  
pp. 1544025 ◽  
Author(s):  
Eduard G. Mychelkin ◽  
Maxim A. Makukov
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Electric Fields ◽  
Scalar Fields ◽  
Mass Scale ◽  
Dark Side ◽  
Spacetime Metric ◽  
Cosmological Scalar ◽  
Static Electric Fields ◽  
The Universe

Starting with geometrical premises, we infer the existence of fundamental cosmological scalar fields. We then consider physically relevant situations in which spacetime metric is induced by one or, in general, by two scalar fields, in accord with the Papapetrou algorithm. The first of these fields, identified with dark energy (DE), has exceedingly small but finite (subquantum) Hubble mass scale ([Formula: see text] eV), and might be represented as a neutral superposition of quasi-static electric fields. The second field is identified with dark matter (DM) as an effectively scalar conglomerate composed of primordial neutrinos and antineutrinos in a special tachyonic state.

Dark matter (energy) may be indistinguishable from modified gravity (MOND)

2017 ◽  
Vol 26 (12) ◽  
pp. 1743010 ◽  
Author(s):  
C. Sivaram
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Modified Gravity ◽  
Observational Evidence ◽  
Negative Results ◽  
Newtonian Dynamics ◽  
Special Cases ◽  
The Universe ◽  
Matter Energy

For Newtonian dynamics to hold over galactic scales, large amounts of dark matter (DM) are required which would dominate cosmic structures. Accounting for the strong observational evidence that the universe is accelerating requires the presence of an unknown dark energy (DE) component constituting about 70% of the matter. Several ingenious ongoing experiments to detect the DM particles have so far led to negative results. Moreover, the comparable proportions of the DM and DE at the present epoch appear unnatural and not predicted by any theory. For these reasons, alternative ideas like MOND and modification of gravity or general relativity over cosmic scales have been proposed. It is shown in this paper that these alternate ideas may not be easily distinguishable from the usual DM or DE hypotheses. Specific examples are given to illustrate this point that the modified theories are special cases of a generalized DM paradigm.

scholarly journals In the Quest for Cosmic Rotation

Universe ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 14 ◽  
Author(s):  
Vladimir A. Korotky ◽  
Eduard Masár ◽  
Yuri N. Obukhov
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Angular Velocity ◽  
Natural Explanation ◽  
Acceleration Parameter ◽  
Electronic Catalogs ◽  
Celestial Sphere ◽  
First Time ◽  
The Universe

This paper analyzes the problem of global rotation in general relativity (GR) theory. Simple cosmological models with rotation and expansion are presented, which give a natural explanation of the modern values of the acceleration parameter at different red shifts without involving the concepts of “dark energy” and “dark matter”. It is shown that due to the smallness of the cosmological rotation, for its detection one should use observations that do not depend on the magnitude of the angular velocity of the Universe. Such tests include the effects of the cosmic mirror and the cosmic lens. For the first time on the basis of modern electronic catalogs the search on the celestial sphere of images of our Galaxy and other galaxies is made. Viable candidates for both effects have been found.

A Clifford-gravity-based cosmology, dark matter and dark energy

2015 ◽  
Vol 12 (03) ◽  
pp. 1550037 ◽  
Author(s):  
Carlos Castro
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Degrees Of Freedom ◽  
Vacuum Energy ◽  
Vacuum Energy Density ◽  
De Sitter ◽  
Four Dimensions ◽  
Accelerating Expansion ◽  
Expansion Of The Universe ◽  
The Universe

A Clifford-gravity-based model is exploited to build a generalized action (beyond the current ones used in the literature) and arrive at relevant numerical results which are consistent with the presently-observed de Sitter accelerating expansion of the universe driven by a very small vacuum energy density ρ obs ~ 10-120(MP)4 (MP is the Planck mass) and provide promising dark energy/matter candidates in terms of the 16 scalars corresponding to the degrees of freedom associated with a Cl (3, 1)-algebra-valued scalar field Φ in four dimensions.

scholarly journals An explanation for dark matter and dark energy consistent with the standard model of particle physics and General Relativity

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Alexandre Deur
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Particle Physics ◽  
Evolution Equations ◽  
Gravitational Interaction ◽  
Interaction Effects ◽  
Law Of Gravity ◽  
The Universe ◽  
Universe Evolution

Abstract Analyses of internal galaxy and cluster dynamics typically employ Newton’s law of gravity, which neglects the field self-interaction effects of General Relativity. This may be why dark matter seems necessary. The universe evolution, on the other hand, is treated with the full theory, General Relativity. However, the approximations of isotropy and homogeneity, normally used to derive and solve the universe evolution equations, effectively suppress General Relativity’s field self-interaction effects and this may introduce the need for dark energy. Calculations have shown that field self-interaction increases the binding of matter inside massive systems, which may account for galaxy and cluster dynamics without invoking dark matter. In turn, energy conservation dictates that the increased binding must be balanced by an effectively decreased gravitational interaction outside the massive system. In this article, such suppression is estimated and its consequence for the Universe’s evolution is discussed. Observations are reproduced without need for dark energy.

scholarly journals Quantum Haplodynamics, Dark Matter, and Dark Energy

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Harald Fritzsch ◽  
Joan Solà
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Bound States ◽  
Vacuum Energy ◽  
Planck Scale ◽  
Cosmic Time ◽  
Vacuum Energy Density ◽  
Scalar State ◽  
The Masses ◽  
The Universe

In quantum haplodynamics (QHD) the weak bosons, quarks, and leptons are bound states of fundamental constituents, denoted as haplons. The confinement scale of the associated gauge groupSU(2)his of the order ofΛh≃0.3 TeV. One scalar state has zero haplon number and is the resonance observed at the LHC. In addition, there exist new bound states of haplons with no counterpart in the SM, having a mass of the order of 0.5 TeV up to a few TeV. In particular, a neutral scalar state with haplon number 4 is stable and can provide the dark matter in the universe. The QHD, QCD, and QED couplings can unify at the Planck scale. If this scale changes slowly with cosmic time, all of the fundamental couplings, the masses of the nucleons and of the DM particles, including the cosmological term (or vacuum energy density), will evolve with time. This could explain the dark energy of the universe.

DENSITY PERTURBATIONS AND THE CHAPLYGIN GAS

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1674-1677
Author(s):  
SANDRO SILVA E COSTA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Spectrum ◽  
Cosmological Model ◽  
Chaplygin Gas ◽  
Scale Factor ◽  
Modified Chaplygin Gas ◽  
Modern Cosmology ◽  
Density Perturbations ◽  
The Universe

One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single 'quartessential' fluid. Following such idea, this work presents a summary of some studies of the evolution of density perturbations in a flat cosmological model with a modified Chaplygin gas acting as a single component. Our goal is to obtain properties of the model which can be used to distinguish it from another cosmological models which have the same solutions for the general evolution of the scale factor of the universe, even without the construction of the power spectrum. Both our analytical and numerical results clearly indicate as one interesting feature of the model the presence of peaks in the evolution of the density constrast.

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