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The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data, provides a powerful tool for constraining cosmological models. Here…

In this study, we propose a reparameterization of a specific viable $f(R)$ gravity model to represent it as a perturbation of the $\Lambda$CDM model. The $f(R)$ gravity model under consideration includes two parameters, $b$ and $n$, which…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-18 A. Oliveros

We use observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), and Cosmic Microwave Background (CMB), along with requirements of Big Bang Nucleosynthesis (BBN), to constrain the cosmological scenarios governed…

High Energy Physics - Theory · Physics 2015-05-14 Sourish Dutta , Emmanuel N. Saridakis

Fluctuations in sky maps of the galaxy redshifts, dubbed as angular redshift fluctuations (ARF), contain precise information about the growth rate of structures and the nature of gravity in the Universe. Specifically, ARF constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Carlos Hernández-Monteagudo , Jonás Chaves-Montero , Raúl E. Angulo , Giovanni Aricò

Modified gravity, known as $f(R)$ gravity, has presently been applied to Cosmology as a realistic alternative to dark energy. For this kind of gravity the expansion of the Universe may accelerate while containing only baryonic and cold dark…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-01 N. Pires , J. Santos , J. S. Alcaniz

We discuss solar system constraints on f(G) gravity models, where f is a function of the Gauss-Bonnet term G. We focus on cosmologically viable f(G) models that can be responsible for late-time cosmic acceleration. These models generally…

High Energy Physics - Theory · Physics 2010-03-26 Antonio De Felice , Shinji Tsujikawa

In the last dozen years a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Ester Piedipalumbo , Enrica Della Moglie , Roberto Cianci

We investigate observational constraints from lensing statistics and high-z type Ia supernovae on flat cosmological models with nonrelativistic matter and an exotic fluid with equation of state, $p_x=(m/3 -1)\rho_x$. We show that agreement…

Astrophysics · Physics 2008-11-26 Ioav Waga , Ana Paula M. R. Miceli

In this review, we outline the expected tests of gravity that will be achieved at cosmological scales in the upcoming decades. We focus mainly on constraints on phenomenologically parameterized deviations from general relativity, which…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-21 Matteo Martinelli , Santiago Casas

Several cosmological measurements have attained significant levels of maturity and accuracy over the last decade. Continuing this trend, future observations promise measurements of the statistics of the cosmic mass distribution at an…

Astrophysics · Physics 2008-11-26 Salman Habib , Katrin Heitmann , David Higdon , Charles Nakhleh , Brian Williams

We revisit the cosmological viability of the Hu $\&$ Sawicki modified gravity scenario. The impact of such a modification on the different cosmological observables, including gravitational waves, is carefully described. The most recent…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-19 Lotfi Boubekeur , Elena Giusarma , Olga Mena , Hector Ramirez

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

We study the dynamics of homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker cosmological models with positive spatial curvature within the context of mimetic gravity theory by employing dynamical system techniques. Our analysis…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Alberto Fritis , Daniel Villalobos-Silva , Yerko Vásquez , Carlos H. López-Caraballo , Juan Carlos Helo

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

We investigate the impact on cosmological observables of $f(Q)$-gravity, a specific class of modified gravity models in which gravity is described by the non-metricity scalar, $Q$. In particular we focus on a specific model which is…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Noemi Frusciante

Modifications of the equations of general relativity at large distances offer one possibility to explain the observed properties of our Universe without invoking a cosmological constant. Numerous proposals for such modified gravity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Fabio Fontanot , Ewald Puchwein , Volker Springel , Davide Bianchi

A new method of measuring cosmology with gamma-ray bursts(GRBs) has been proposed by Liang and Zhang recently. In this method, only observable quantities including the rest frame peak energy of the \nu F_\nu spectrum (E'_p), the isotropic…

Astrophysics · Physics 2009-11-13 F. Y. Wang , Z. G. Dai

Models of modified gravity offer promising alternatives to the concordance $\Lambda$CDM cosmology to explain the late-time acceleration of the universe. A popular such model is $f(R)$ gravity, in which the Ricci scalar in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-14 Christine Corbett Moran , Romain Teyssier , Baojiu Li

Gamma-ray bursts (GRBs), as a possible probe to extend the Hubble diagram to high redshifts, have attracted much attention recently. In this paper, we select two samples of GRBs that have a plateau phase in X-ray afterglow. One is short…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 J. P. Hu , F. Y. Wang , Z. G. Dai

Modified gravitational forces in models that seek to explain cosmic acceleration without dark energy typically predict deviations in the abundance of massive dark matter halos. We conduct the first, simulation calibrated, cluster abundance…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Fabian Schmidt , Alexey Vikhlinin , Wayne Hu
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