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Related papers: {\Lambda}CDM cosmology from visible matter only

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In this note, we explore the thermodynamic properties of the universe in the background of the generalized energy-momentum-squared gravity. We derive the energy density of matter from the non-standard continuity equation and use it in our…

General Relativity and Quantum Cosmology · Physics 2021-06-23 Prabir Rudra , Behnam Pourhassan

We establish in a cosmological model based on Lyra's geometry a relationship between a displacement vector field $ \phi_{\mu} $, the Hubble parameter and the matter energy density $ \rho_{m} $ (with a constant equation of state $0 \le…

General Relativity and Quantum Cosmology · Physics 2013-05-08 Hoavo Hova

Based on Padmanabhan's theory, the spatial expansion of the Universe can be explained by the emergence of space as cosmic time progresses. To further explore this idea, we have developed fractional-fractal Friedmann and Raychaudhuri…

General Relativity and Quantum Cosmology · Physics 2023-09-29 P. F. da Silva Junior , E. W. de Oliveira Costa , S. Jalalzadeh

It is argued that many of the problems and ambiguities of standard cosmology derive from a single one: violation of conservation of energy in the standard paradigm. Standard cosmology satisfies conservation of local energy, however…

General Physics · Physics 2017-10-02 Herman Telkamp

In this work we consider a flat cosmological model with a set of fluids in the framework of supersymmetric cosmology. The obtained supersymmetric algebra allowed us to take quantum solutions. It is shown that only in the case of a…

General Relativity and Quantum Cosmology · Physics 2010-12-23 J. J. Rosales , V. I. Tkach

It is generally assumed that the two dark components of the energy density of the universe, a smooth component called dark energy and a fluid of nonrelativistic weakly interacting particles called dark matter, are independent of each other…

Astrophysics · Physics 2007-05-23 Mark B. Hoffman

The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…

Astrophysics · Physics 2008-11-26 J. Besprosvany

The $\Lambda$CDM model, or concordance cosmology, as it is often called, is a paradigm at its maturity. It is clearly able to describe the universe at large scale, even if some issues remain open, such as the cosmological constant problem ,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-27 Antonino Del Popolo , Morgan Le Delliou

We make the hypothesis that the velocity of light and the expansion of the universe are two aspects of one single concept connecting space and time in the expanding universe. We show that solving Friedman's equations with that…

Astrophysics · Physics 2009-06-23 J. -M. Vigoureux , P. Vigoureux , B. Vigoureux

We construct a cosmological model which is physically reasonable, mathematically tractable, and extends the study of CDM models to the case where the equations of state (EoS) for matter and dark energy (DE) vary with time. It is based on…

General Relativity and Quantum Cosmology · Physics 2012-06-14 J. Ponce de Leon

Interacting dark energy-dark matter models have been widely analyzed in the literature in an attempt to find traces of new physics beyond the usual cosmological ($\Lambda$CDM) models. Such a coupling between both dark components is usually…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Diego Álvarez-Ortega , Gonzalo J. Olmo , Diego Rubiera-García , Diego Sáez-Chillón Gómez

The standard LambdaCDM model of cosmology is usually understood to arise from demanding that the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric satisfy the General Relativity dynamics for spacetime metrics. The FLRW data-based dominant…

General Physics · Physics 2009-07-13 Reginald T Cahill

The $\Lambda$CDM cosmological model faces increasingly significant and robust tensions among independent cosmological probes, prompting renewed scrutiny of its foundational assumptions. While General Relativity and the nature of dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 S. M. Koksbang , A. Heinesen

The $\rm\Lambda$CDM cosmological model is remarkable: with just 6 parameters it describes the evolution of the Universe from a very early time when all structures were quantum fluctuations on subatomic scales to the present, and it is…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-07 Michael S. Turner

The dark energy plus cold dark matter ($\Lambda$CDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of Universe and its evolution with time. Yet on length scales…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 James S. Bullock , Michael Boylan-Kolchin

Within the Machian model of the universe the dark energy is identified with the Machian energy of collective gravitational interactions of all particles inside the horizon. It is shown that the fine structure constant can be expressed in…

General Relativity and Quantum Cosmology · Physics 2010-09-28 Merab Gogberashvili , Igor Kanatchikov

In previous work [L. Blanchet and A. Le Tiec, Phys. Rev. D 78, 024031 (2008)], a model of dark matter and dark energy based on the concept of gravitational polarization was investigated. This model was shown to recover the concordance…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Luc Blanchet , Alexandre Le Tiec

The asymmetric dark matter (ADM) paradigm is motivated by the apparent coincidence between the cosmological mass densities of visible and dark matter, $\Omega_\mathrm{DM} \simeq 5\Omega_\mathrm{VM}$. However, most ADM models only relate the…

High Energy Physics - Phenomenology · Physics 2023-02-15 Alexander C. Ritter , Raymond R. Volkas

Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter…

General Physics · Physics 2008-11-09 Walter Petry

In the last decades, a cosmological model that fits observations through a vast range of scales emerged. It goes under the name of ${\Lambda}$CDM. However, there are still challenging questions that remain unanswered by this model, such as…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-25 Michele Mancarella
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