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This study investigates the dynamics of a spatially homogeneous and anisotropic LRS Bianchi type-I universe with viscous fluid in the framework of $f(Q)$ symmetric teleparallel gravity. We assume a linear form for $f(Q)$ and introduce…

General Relativity and Quantum Cosmology · Physics 2024-04-16 M. Koussour , S. H. Shekh , M. Bennai , N. Myrzakulov

A simple model of uniformly expanding, homogeneous Universe with a bulk viscosity is studied wherein the inflationary density decays due to viscous dissipation during the expansion phase of the Universe. The model is shown to generate the…

General Relativity and Quantum Cosmology · Physics 2020-10-14 Sanved Kolekar , S. Shankaranarayanan , S. M. Chitre

A generalized dynamical equation for the scale factor of the universe is proposed to describe the cosmological evolution, of which the $\Lambda$CDM model is a special case. It also provides a general example to show the equivalence of the…

Astrophysics · Physics 2009-11-11 J. Ren , X. H. Meng

The cosmic curvature $\Omega_{K}$ is an important parameter related to the inflationary cosmology and the ultimate fate of the universe. In this work, we adopt the non-CMB observations to constrain $\Omega_{K}$ in the $\Lambda$CDM model and…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Peng-Ju Wu , Xin Zhang

We investigate the validity of the Cosmological Principle by constraining the cosmological parameters $H_0$ and $q_0$ through the celestial sphere. Our analyses are performed in a low-redshift regime in order to follow a model independent…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-04 C. A. P. Bengaly, , A. Bernui , J. S. Alcaniz

In this paper, we present a scheme to investigate the opacity of the Universe in a cosmological-model-independent way, with the combination of current and future measurements of type Ia supernova sample and galactic-scale strong…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Yu-Bo Ma , Shuo Cao , Jia Zhang , Jingzhao Qi , Tonghua Liu , Yuting Liu , Shuaibo Geng

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are…

Astrophysics · Physics 2015-05-13 L. D. Ferramacho , A. Blanchard , Y. Zolnierowski

We use the Radial Baryon Acoustic Oscillation (RBAO) measurements, distant type Ia supernovae (SNe Ia), the observational $H(z)$ data (OHD) and the Cosmic Microwave Background (CMB) shift parameter data to constrain cosmological parameters…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Zhong-Xu Zhai , Hao-Yi Wan , Tong-Jie Zhang

We consider some background tests of standard cosmology in the context of Horava gravity with different scaling dimensions for space and time, which has been proposed as a renormalizable, higher-derivative, Lorentz-violating quantum gravity…

High Energy Physics - Theory · Physics 2022-10-19 Nils A. Nilsson , Mu-In Park

Exact solutions for a model with variable $G$, $\Lambda$ and bulk viscosity are obtained. Inflationary solutions with constant (de Sitter-type) and variable energy density are found. An expanding anisotropic universe is found to isotropize…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Arbab I. Arbab

Inspired by the recent conjecture originated from graduated dark energy that the Universe has recently transitioned from anti-de Sitter vacua to de Sitter vacua, we extend the $\Lambda$CDM model by a cosmological constant ($\Lambda_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-07 Ozgur Akarsu , Suresh Kumar , Emre Ozulker , J. Alberto Vazquez

It has been recently shown that the presence of a vector field over cosmological scales could explain the observed accelerated expansion of the universe without introducing neither new scales nor unnatural initial conditions in the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jose Beltran Jimenez , Ruth Lazkoz , Antonio L. Maroto

In the generalized matter-geometry coupling theory, we investigate the physical characteristics and causality of some new cosmological models for a flat, homogeneous, and isotropic spacetime filled with stiff, radiation, dust, and curvature…

General Relativity and Quantum Cosmology · Physics 2025-04-10 Dinesh Chandra Maurya , Javlon Rayimbaev , Inomjon Ibragimov , Sokhibjan Muminov

We use the physically-consistent tilted spatially-flat and untilted non-flat $\Lambda$CDM inflation models to constrain cosmological parameter values with the Planck 2015 cosmic microwave background (CMB) anisotropy data and recent Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-19 Chan-Gyung Park , Bharat Ratra

In this work we investigate the utility of using SNe Ia observations in constraining the cosmological parameters in BSBM theory where a scalar field is responsible for both fine structure constant variation and late time universe…

General Relativity and Quantum Cosmology · Physics 2015-06-04 H. Farajollahi , A. Salehi

We present constraints on extensions to the $\Lambda$CDM cosmological model from measurements of the $E$-mode polarization auto-power spectrum and the temperature-$E$-mode cross-power spectrum of the cosmic microwave background (CMB) made…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 L. Balkenhol , D. Dutcher , P. A. R. Ade , Z. Ahmed , E. Anderes , A. J. Anderson , M. Archipley , J. S. Avva , K. Aylor , P. S. Barry , R. Basu Thakur , K. Benabed , A. N. Bender , B. A. Benson , F. Bianchini , L. E. Bleem , F. R. Bouchet , L. Bryant , K. Byrum , J. E. Carlstrom , F. W. Carter , T. W. Cecil , C. L. Chang , P. Chaubal , G. Chen , H. -M. Cho , T. -L. Chou , J. -F. Cliche , T. M. Crawford , A. Cukierman , C. Daley , T. de Haan , E. V. Denison , K. Dibert , J. Ding , M. A. Dobbs , W. Everett , C. Feng , K. R. Ferguson , A. Foster , J. Fu , S. Galli , A. E. Gambrel , R. W. Gardner , N. Goeckner-Wald , R. Gualtieri , S. Guns , N. Gupta , R. Guyser , N. W. Halverson , A. H. Harke-Hosemann , N. L. Harrington , J. W. Henning , G. C. Hilton , E. Hivon , G. P. Holder , W. L. Holzapfel , J. C. Hood , D. Howe , N. Huang , K. D. Irwin , O. B. Jeong , M. Jonas , A. Jones , T. S. Khaire , L. Knox , A. M. Kofman , M. Korman , D. L. Kubik , S. Kuhlmann , C. -L. Kuo , A. T. Lee , E. M. Leitch , A. E. Lowitz , C. Lu , S. S. Meyer , D. Michalik , M. Millea , J. Montgomery , A. Nadolski , T. Natoli , H. Nguyen , G. I. Noble , V. Novosad , Y. Omori , S. Padin , Z. Pan , P. Paschos , J. Pearson , C. M. Posada , K. Prabhu , W. Quan , A. Rahlin , C. L. Reichardt , D. Riebel , B. Riedel , M. Rouble , J. E. Ruhl , J. T. Sayre , E. Schiappucci , E. Shirokoff , G. Smecher , J. A. Sobrin , A. A. Stark , J. Stephen , K. T. Story , A. Suzuki , K. L. Thompson , B. Thorne , C. Tucker , C. Umilta , L. R. Vale , K. Vanderlinde , J. D. Vieira , G. Wang , N. Whitehorn , W. L. K. Wu , V. Yefremenko , K. W. Yoon , M. R. Young

We use HII starburst galaxy apparent magnitude measurements to constrain cosmological parameters in six cosmological models. A joint analysis of HII galaxy, quasar angular size, baryon acoustic oscillations peak length scale, and Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-14 Shulei Cao , Joseph Ryan , Bharat Ratra

In this work, we have proposed a general dark energy density parametrization to study the evolution of the universe. We have also constrained the model parameters using the combination of Type Ia supernova (SNIa), baryonic acoustic…

General Relativity and Quantum Cosmology · Physics 2018-07-25 Abdulla Al Mamon
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