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Related papers: Dynamical Dark Energy Emerges from Massive Gravity

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The dynamical aspect of accelerating cosmological model has been studied in this paper in the context of modified symmetric teleparallel gravity, the $f(Q)$ gravity. Initially, we have derived the dynamical parameters for two well known…

General Relativity and Quantum Cosmology · Physics 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

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

String theory naturally leads to the expectation that dark energy is not stable, and may be evolving as captured by the Swampland de Sitter conjectures. Moreover, motivated by the distance conjecture, a unification of dark sector has been…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-21 Alek Bedroya , Georges Obied , Cumrun Vafa , David H. Wu

In this paper, we examine the acceleration of the Universe's expansion in $F(R,T)$ gravity, where $R$ denotes the Ricci scalar and $T$ the trace of energy-momentum tensor. Indeed, the unknown nature of the source controlling this…

General Relativity and Quantum Cosmology · Physics 2024-04-25 Ahmed Errahmani , Amine Bouali , Safae Dahmani , Imad El Bojaddaini , Taoufik Ouali

Dark energy must be taken into account to estimate more reliably the amount of dark matter and how it is distributed in the local universe. For systems several Mpc across like the Local Group, we introduce three self-consistent independent…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-24 A. D. Chernin , P. Teerikorpi , M. J. Valtonen , G. G. Byrd , V. P. Dolgachev , L. M. Domozhilova

The Phenomenologically Emergent Dark Energy model, a dark energy model with the same number of free parameters as the flat $\Lambda$CDM, has been proposed as a working example of a minimal model which can avoid the current cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Weiqiang Yang , Eleonora Di Valentino , Supriya Pan , Olga Mena

A new phenomenological dark energy model, originally associated to the large-scale structure formation and considered as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the…

General Relativity and Quantum Cosmology · Physics 2026-03-05 A. Kazım Çamlıbel

We study the cosmological evolution of an induced gravity model with a self-interacting scalar field $\sigma$ and in the presence of matter and radiation. Such model leads to Einstein Gravity plus a cosmological constant as a stable…

Astrophysics · Physics 2008-11-26 F. Finelli , A. Tronconi , G. Venturi

One of the greatest challenges in cosmology today is to determine the nature of dark energy, the source of the observed present acceleration of the universe. High precision experiments are being developed to reduce the uncertainties in the…

Astrophysics · Physics 2007-05-23 Reuven Opher , Ana Pelinson

For the first time, we reconstruct the dark energy equation of the state parameter $w$ from the combination of background and perturbation observations, specifically combining the Hubble parameter data from cosmic chronometer observations…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-15 Bikash R. Dinda , Narayan Banerjee

We present a Dark Energy (DE) model with a sound derivation as a natural extension of the Standard Model of particle physics with no free parameters and an excellent fit with current cosmological data improving by 21% the $\Lambda$CDM fit…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 A. de la Macorra , E. Almaraz

Dark matter is fundamental to the composition, structure, and evolution of the universe. Combining the ACT's cosmic microwave background, DESI's baryon acoustic oscillations with DESY5 type Ia supernova observations, we find a $3.4\,\sigma$…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Deng Wang , Kazuharu Bamba

In this paper, we give a conceptual explanation of dark energy as a small negative residual scalar curvature present even in empty spacetime. This curvature ultimately results from postulating a discrete spacetime geometry, very closely…

Mathematical Physics · Physics 2012-08-16 Aaron Trout

Given a class of dark energy models, constraints from one set of cosmic acceleration observables make predictions for other observables. Here we present the allowed ranges for the expansion rate H(z), distances D(z), and the linear growth…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-23 Michael J. Mortonson , Wayne Hu , Dragan Huterer

The accelerated expansion of the universe poses a significant challenge to General Relativity. Non-local modifications to gravity have emerged as a compelling class of theories to address this dark energy puzzle. Building upon earlier…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Susobhan Mandal , S. Shankaranarayanan

In this paper we introduce the fractional dark energy model, in which the accelerated expansion of the Universe is driven by a nonrelativistic gas (composed by either fermions or bosons) with a noncanonical kinetic term. The kinetic energy…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-20 Ricardo G. Landim

Recent measurements suggest our universe has a substantial dark energy component, which is usually interpreted in terms of a cosmological constant. Here we examine how much the form of this dark energy can be modified while still retaining…

High Energy Physics - Phenomenology · Physics 2009-11-07 Duane A. Dicus , Wayne W. Repko

Recent results from the Dark Energy Spectroscopic Instrument (DESI) collaboration have been interpreted as evidence for evolving dark energy. However, this interpretation is strongly dependent on which Type Ia supernova (SN) sample is…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-04 George Efstathiou

We present observational constraints on the Bound Dark Energy Cold Dark Matter (BDE-CDM) model using DESI DR2 baryon acoustic oscillation measurements combined with Planck CMB data and Type Ia supernovae compilations (PantheonPlus, Union3,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-15 Axel de la Macorra , Jose Agustin Lozano Torres

There is something unknown in the cosmos. Something big. Which causes the acceleration of the Universe expansion, that is perhaps the most surprising and unexpected discovery of the last decades, and thus represents one of the most pressing…

General Physics · Physics 2013-04-18 M. Villata
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