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Related papers: Cosmological model with energy transfer

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To find more deliberate f(R,T) cosmological solutions, we proceed our previous paper further by studying some new aspects of the considered models via investigation of some new cosmological parameters/quantities to attain the most…

General Relativity and Quantum Cosmology · Physics 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

Cosmology has entered an era of unprecedented precision, yet increasing accuracy has revealed cracks in the standard $\Lambda$CDM paradigm. Although the model remains highly successful when confronted with individual datasets, joint…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-06 Eleonora Di Valentino

We examine cyclic phantom models for the universe, in which the universe is dominated sequentially by radiation, matter, and a phantom dark energy field, followed by a standard inflationary phase. Since this cycle repeats endlessly, the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Hui-Yiing Chang , Robert J. Scherrer

We study a power-law $F(R)$ gravity with an early dark energy term, that can describe both the early-time and the late-time acceleration of the Universe. We confront this scenario with recent observational data including the Pantheon Type…

General Relativity and Quantum Cosmology · Physics 2023-06-28 Sergei D. Odintsov , V. K. Oikonomou , German S. Sharov

Several dark energy models on the brane are investigated. They are compared with corresponding theories in the frame of 4d Friedmann-Robertson-Walker cosmology. To constrain the parameters of the models considered, recent observational…

General Relativity and Quantum Cosmology · Physics 2015-06-12 A. V. Astashenok , E. Elizalde , J. de Haro , S. D. Odintsov , A. V. Yurov

We consider ever-expanding Big Bang models with a cosmological constant, $\Lambda$, and investigate in detail the evolution of the observable part of the universe. We also discuss quintessence models from the same point of view. A new…

Astrophysics · Physics 2009-11-06 Einar H. Gudmundsson , Gunnlaugur Bjornsson

In this study, we will look at an interacting dark energy model. In the framework of Friedmann-Robertson-Walker (FRW) space-time, we have made the hypothesis of an interacting scheme between two fields (dark matter (DM) and dark energy…

General Relativity and Quantum Cosmology · Physics 2023-11-27 J. K. Singh , Ritika Nagpal

The tension between measurements of the Hubble constant obtained at different redshifts may provide a hint of new physics active in the relatively early universe, around the epoch of matter-radiation equality. A leading paradigm to resolve…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Mariana Carrillo González , Qiuyue Liang , Jeremy Sakstein , Mark Trodden

Using the first law of thermodynamics, we propose a relation between the system entropy ($S$) and its IR ($L$) and UV ($\Lambda$) cutoffs. In addition, applying this relation to the apparent horizon of flat FRW universe, whose entropy meets…

General Physics · Physics 2018-10-18 H. Moradpour , S. A. Moosavi , I. P. Lobo , J. P. Morais Graça , A. Jawad , I. G. Salako

Entropic cosmology with the R\'{e}nyi entropy of the apparent horizon $S_R=(1/\alpha)\ln(1+\alpha S_{BH})$, where $S_{BH}$ is the Bekenstein--Hawking entropy, is studied. By virtue of the thermodynamics-gravity correspondence a model of…

General Physics · Physics 2026-05-04 S. I. Kruglov

This paper investigates the effects of spatial curvature in a model where dark matter and dark energy interact. The analysis employs a range of datasets, including CMB, BAO, Type Ia Supernova, $H(z)$ from cosmic chronometers, $H_0$…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-28 Trupti Patil , Sukanta Panda

In this paper a new theory of Dark Matter is proposed. Experimental analysis of several Galaxies show how the non-gravitational contribution to galactic Velocity Rotation Curves can be interpreted as that due to the Cosmological Constant…

Astrophysics · Physics 2007-05-23 G. V. Kraniotis , S. B. Whitehouse

This article revisits the interpretation of cosmic probes such as SNIa and BAO under a two-regions model of the universe. Standard cosmological analyses assume homogeneity, yet observations are predominantly conducted in overdense regions…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-21 Vincent Deledicque

We study the extent up to which the equivalence principle is obeyed in models of modified gravity and dark energy involving a single scalar degree of freedom. We focus on the effective field theories of dark energy describing the late time…

High Energy Physics - Theory · Physics 2020-01-08 Lasma Alberte

We investigate the viability of a cosmological scenario with interacting dark sector, which can describe the coexistence between dark energy and dark matter. The model possesses an analytical solution for the Hubble function and we…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Shambel Sahlu , Andronikos Paliathanasis , Genly Leon , Amare Abebe

The Hubble constant inferred from the 6-parameter fit to the CMB power spectrum conflicts with the value obtained from direct measurements via type Ia supernova and Cepheids observations. We write down effective operators involving spin-0,…

High Energy Physics - Phenomenology · Physics 2023-11-14 Alvaro S. de Jesus , Nelson Pinto-Neto , Farinaldo S. Queiroz , Joseph Silk , Dêivid R. da Silva

We study cosmological perturbations in a model of unified dark matter and dark energy with a sharp transition in the late-time universe. The dark sector is described by a dark fluid which evolves from an early stage at redshifts $z > z_C$…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Rodrigo R. Cuzinatto , Léo G. Medeiros , Eduardo M. de Morais , Robert H. Brandenberger

The recently observed accelerated expansion of the universe has put a challenge for its theoretical understanding. As a possible explanation of this, it is considered that the most part of the present universe is filled with a form of…

In standard cosmologies, dark energy interacts only gravitationally with dark matter. There could be a non-gravitational interaction in the dark sector, leading to changes in the effective DE equation of state, in the redshift dependence of…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-13 Timothy Clemson , Kazuya Koyama , Gong-Bo Zhao , Roy Maartens , Jussi Väliviita

Recent supernovae of type Ia measurements and other astronomical observations suggest that our universe is in accelerating phase of evolution at the present epoch. While a dark energy of unknown form is usually proposed as the most feasible…

Astrophysics · Physics 2008-11-26 Andrzej Borowiec , Wlodzimierz Godlowski , Marek Szydlowski
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