scholarly journals The Λ and the CDM as Integration Constants

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2076
Author(s):  
Priidik Gallagher ◽  
Tomi Koivisto
Keyword(s):  
Dark Matter ◽  
Gauge Theory ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Spontaneous Symmetry Breaking ◽  
First Principles ◽  
Cold Dark Matter ◽  
Dark Sector ◽  
Λcdm Model ◽  
The Universe

Notoriously, the two main problems of the standard ΛCDM model of cosmology are the cosmological constant Λ and the cold dark matter, CDM. This essay shows that both the Λ and the CDM arise as integration constants in a careful derivation of Einstein’s equations from first principles in a Lorentz gauge theory. The dark sector of the universe might only reflect the geometry of a spontaneous symmetry breaking that is necessary for the existence of spacetime and an observer therein.

scholarly journals Interactions in the dark sector of the Universe

2014 ◽  
Vol 11 (02) ◽  
pp. 1460014 ◽  
Author(s):  
Winfried Zimdahl
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Dark Sector ◽  
Future Evolution ◽  
Evolution Of The Universe ◽  
Λcdm Model ◽  
The Future ◽  
The Universe

Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the ΛCDM model. We review main features of several recently studied models with nongravitational couplings between dark matter and dark energy.

scholarly journals Cold dark matter: Bose-Einstein condensation of gluons in Anti-de Sitter space time

2021 ◽  
Author(s):  
Gilles Cohen-Tannoudji ◽  
Jean-Pierre Gazeau
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Standard Model ◽  
Cosmological Constant ◽  
Cold Dark Matter ◽  
Hidden Variables ◽  
Einstein Condensation ◽  
De Sitter ◽  
Bose Einstein ◽  
The Universe

In the same way as the realization of some of the famous gedanken experiments imagined by the founding fathers of quantum mechanics has recently led to the current renewal of the interpretation of quantum physics, it seems that the most recent progresses of observational astrophysics can be interpreted as the realization of some cosmological gedanken experiments such as the removal from the universe of the whole visible matter or the cosmic time travel leading to a new cosmological standard model. This standard model involves two dark components of the universe, dark energy and dark matter. Whereas dark energy is usually associated with the positive cosmological constant, we propose to explain dark matter as a pure QCD effect. This effect is due to the trace anomaly viewed as a negative cosmological constant accompanying baryonic matter at the hadronization transition from the quark gluon plasma phase to the colorless hadronic phase. Our approach not only yields a ratio Dark/Visible equal to 11/2 but also provides gluons and (anti-)quarks with an extra mass of vibrational nature. Currently observed dark matter is thus interpreted as a gluon Bose Einstein condensate that is a relic of the quark period. Such an interpretation would comfort the idea that, apart from the violation of the matter/antimatter symmetry satisfying the Sakharov’s conditions, the reconciliation of particle physics and cosmology needs not the recourse to any ad hoc fields, particles or hidden variables.

scholarly journals SOLVING THE INVERSE PROBLEM WITH INHOMOGENEOUS UNIVERSES

2011 ◽  
Vol 01 ◽  
pp. 234-239
Author(s):  
CHUL-MOON YOO ◽  
TOMOHIRO KAI ◽  
KEN-ICHI NAKAO
Keyword(s):  
Inverse Problem ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Big Bang ◽  
Universe Model ◽  
Cosmological Redshift ◽  
Λcdm Model ◽  
The Big Bang ◽  
The Universe ◽  
Dust Universe

We construct the Lemaître-Tolman-Bondi (LTB) dust universe whose distance-redshift relation is equivalent to that in the concordance Λ cold dark matter (ΛCDM) cosmological model. In our model, the density distribution and velocity field are not homogeneous, whereas the big-bang time is uniform, which implies that the universe is homogeneous at its beginning. We also study the temporal variation of the cosmological redshift and show that, by the observation of this quantity, we can distinguish our LTB universe model from the concordance ΛCDM model, even if their redshift-distance relations are equivalent to each other.

scholarly journals BAYESIAN ANALYSIS OF THE CHAPLYGIN GAS AND COSMOLOGICAL CONSTANT MODELS USING THE SNe Ia DATA

2004 ◽  
Vol 13 (04) ◽  
pp. 669-693 ◽  
Author(s):  
R. COLISTETE ◽  
J. C. FABRIS ◽  
S. V. B. GONÇALVES ◽  
P. E. DE SOUZA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Confidence Level ◽  
Cold Dark Matter ◽  
Chaplygin Gas ◽  
Type Ia Supernovae ◽  
Λcdm Model ◽  
Type Ia ◽  
Ia Supernovae ◽  
The Universe

The type Ia supernovae observational data are used to estimate the parameters of a cosmological model with cold dark matter and the Chaplygin gas. This exotic gas, which is characterized by a negative pressure varying with the inverse of density, represents in this model the dark energy responsible for the acceleration of the Universe. The Chaplygin gas model depends essentially on four parameters: the Hubble constant, the velocity of the sound of the Chaplygin gas, the curvature of the Universe and the fraction density of the Chaplygin gas and the cold dark matter. The Bayesian parameter estimation yields [Formula: see text] and [Formula: see text]. These and other results indicate that a Universe completely dominated by the Chaplygin gas is favoured, what reinforces the idea that the Chaplygin gas may unify the description for dark matter and dark energy, at least as the type Ia supernovae data are concerned. A closed and accelerating Universe is also favoured. The Bayesian statistics indicates that the Chaplygin gas model is more likely than the standard cosmological constant (ΛCDM) model at 55.3% confidence level when an integration on all free parameters is performed. Assuming the spatially flat curvature, this percentage mounts to 65.3%. On the other hand, if the density of dark matter is fixed at zero value, the Chaplygin gas model becomes more preferred than the ΛCDM model at 91.8% confidence level. Finally, the hypothesis of flat Universe and baryonic matter (Ωb0=0.04) implies a Chaplygin gas model preferred over the ΛCDM at a confidence level of 99.4%.

The Averaged Null Energy Condition and the Madelung Constant for Cold Dark Matter and Energy

2014 ◽  
Vol 69 (1-2) ◽  
pp. 17-20
Author(s):  
Friedwardt Winterberg
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Cosmological Constant ◽  
Relative Abundance ◽  
Cold Dark Matter ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Negative Mass ◽  
Madelung Constant ◽  
The Universe

To explain the relative abundance of the dark energy and non-baryonic cold dark matter (74% and 22% respectively), making up 96% of the material content of the universe, it is proposed that space is filled with an equal amount of positive and negative mass particles, satisfying the average null energy condition, and with it the smallness of the cosmological constant. This assumption can explain the relative abundance of the dark energy and cold dark matter by the Madelung constant for the gravitationally-interacting positive and negative mass particles.

scholarly journals DARK ENERGY IN AN AXION MODEL WITH EXPLICIT Z(N) SYMMETRY BREAKING

2005 ◽  
Vol 20 (23) ◽  
pp. 1763-1766 ◽  
Author(s):  
PANKAJ JAIN
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Symmetry Breaking ◽  
Cold Dark Matter ◽  
Symmetry Breaking Term ◽  
The Universe ◽  
Breaking Term

We point out that a well-known axion model with an explicit Z(N) symmetry breaking term predicts both dark energy and cold dark matter. We estimate the parameters of this model which fit the observed densities of the dark components of the universe. We find that the parameters do not conflict with any observations.

COSMOLOGICAL CONSTANT, PLANCK MASS, HUBBLE MASS AND AXION: A RELATION THROUGH HIGHER-ORDER LOOPS COLEMAN-WEINBERG POTENTIAL WITH WEINBERG/LANDAU GAUGE

2020 ◽  
Author(s):  
Rami Ahmad El-Nabulsi
Keyword(s):  
Dark Matter ◽  
Cosmological Constant ◽  
Cold Dark Matter ◽  
Vacuum Energy ◽  
Landau Gauge ◽  
Higher Order ◽  
Planck Mass ◽  
Higgs Vacuum ◽  
Scalar Mass ◽  
The Universe

In this communication, a conformal coupling gravity is discussed in the presence of a complex Coleman-Weinberg potential which is generated from the contributions from 1st, 2nd and all higher order loops. A relation between the cosmological constant, the Hubble mass and the Higgs vacuum energy is obtained in particular when Weinberg/Landau gauge is used. Moreover, it was observed that the removal of the logarithmic mass boosts the scalar mass from Hubble mass of order 10<sup>−33 </sup>eV to 2.47× 10<sup>−3</sup>eV which is comparable to the mass of non-baryonic Cold Dark Matter or axion based on recent observations and which constitutes about 84% of all matter in the Universe.

scholarly journals Cosmology with Type II supernovae

2019 ◽  
Vol 28 (08) ◽  
pp. 1950106
Author(s):  
Deng Wang
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Cold Dark Matter ◽  
New Physics ◽  
Type Ii ◽  
Acoustic Oscillations ◽  
Dark Sector ◽  
Dark Energy Density ◽  
Type Ia ◽  
The Universe

With the recent progresses on the Type II supernovae, we attempt to investigate whether there does exist new physics beyond the standard cosmological paradigm, i.e. the cosmological constant [Formula: see text] plus cold dark matter ([Formula: see text]CDM). Constraining four alternative cosmological models with a data combination of currently available Type II supernovae calibrated by the standard color method, Type Ia supernovae, baryon acoustic oscillations (BAO), cosmic microwave background (CMB) and cosmic chronometers, at the [Formula: see text] confidence level, we find that (i) a spatially flat universe is supported for the nonflat [Formula: see text]CDM model; (ii) the constrained equation-of-state of dark energy [Formula: see text] is consistent with the [Formula: see text]CDM hypothesis for the [Formula: see text]CDM model, where [Formula: see text] is a free parameter; (iii) for the decaying vacuum model, there is no evidence of interaction between dark matter and dark energy in the dark sector of the universe; (iv) there is also no hint of dynamical dark energy for the dark energy density-parametrization scenario. It is very obvious that a larger Type II supernovae sample is required if we expect to draw definitive conclusions about the formation and evolution of the universe.

Ω0 Concordance

2005 ◽  
Vol 201 ◽  
pp. 271-281
Author(s):  
Masataka. Fukugita
Keyword(s):  
Dark Matter ◽  
Cosmological Constant ◽  
Structure Formation ◽  
Cold Dark Matter ◽  
Mass Density ◽  
Hubble Constant ◽  
Density Parameter ◽  
Microwave Background ◽  
The Hierarchical Structure ◽  
The Universe

The determinations of the mass density parameter Ω0 are examined with a particular emphasis given to the new cosmic microwave background (CMB) experiments. It is shown that the Ω0 and the Hubble constant H0 from CMB are quite consistent with those from other observations with the aid of the hierarchical structure formation models based on cold dark matter dominance with the cosmological constant that makes the universe flat. The concordance value of Ω0 is 0.25-0.45.

scholarly journals Inverse Seesaw, dark matter and the Hubble tension

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
E. Fernandez-Martinez ◽  
M. Pierre ◽  
E. Pinsard ◽  
S. Rosauro-Alcaraz
Keyword(s):  
Dark Matter ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Degrees Of Freedom ◽  
Lepton Number ◽  
Neutrino Masses ◽  
Sterile Neutrinos ◽  
Seesaw Mechanism ◽  
The Universe ◽  
Matter Component

AbstractWe consider the inverse Seesaw scenario for neutrino masses with the approximate Lepton number symmetry broken dynamically by a scalar with Lepton number two. We show that the Majoron associated to the spontaneous symmetry breaking can alleviate the Hubble tension through its contribution to $$\Delta N_\text {eff}$$ Δ N eff and late decays to neutrinos. Among the additional fermionic states required for realizing the inverse Seesaw mechanism, sterile neutrinos at the keV-MeV scale can account for all the dark matter component of the Universe if produced via freeze-in from the decays of heavier degrees of freedom.

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