English
Related papers

Related papers: Low redshift constraints on scale-covariant models

200 papers

Soft cosmology is an extension of standard cosmology allowing for a scale-dependent equation-of-state (EoS) parameter in the dark sectors, which is one of the properties of soft materials in condensed-matter physics, that may arise either…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-12 Emmanuel N. Saridakis , Weiqiang Yang , Supriya Pan , Fotios K. Anagnostopoulos , Spyros Basilakos

We use the Simon, Verde, & Jimenez (2005) determination of the redshift dependence of the Hubble parameter to constrain cosmological parameters in three dark energy cosmological models. We consider the standard $\Lambda$CDM model, the XCDM…

Astrophysics · Physics 2011-02-11 Lado Samushia , Bharat Ratra

We analyse various low-redshift cosmological data from Type-Ia Supernova, Baryon Acoustic Oscillations, Time-Delay measurements using Strong-Lensing, $H(z)$ measurements using Cosmic Chronometers and growth measurements from large scale…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Koushik Dutta , Anirban Roy , Ruchika , Anjan A Sen , M. M. Sheikh-Jabbari

We consider a varieties of quintessence scalar field models in a homogeneous and isotropic geometry of the universe with zero spatial curvature aiming to provide stringent constraints using a series of cosmological data sets, namely, the…

General Relativity and Quantum Cosmology · Physics 2019-07-24 Weiqiang Yang , M. Shahalam , Barun Pal , Supriya Pan , Anzhong Wang

Flat $\Lambda$CDM cosmology is specified by two constant fitting parameters at the background level in the late Universe, the Hubble constant $H_0$ and matter density (today) $\Omega_m$. Mathematically, $H_0$ and $\Omega_m$ are either…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-19 Eoin Ó Colgáin , M. M. Sheikh-Jabbari , Rance Solomon , Maria G. Dainotti , Dejan Stojkovic

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

We are at a specific period of modern cosmology, during which the large increase of the amount of data leads to the idea that the determination of cosmological parameters has been achieved with a rather good precision. There is a large…

Astrophysics · Physics 2017-08-23 A. Blanchard

The canonical cosmological model to explain the recent acceleration of the universe relies on a cosmological constant, and most dynamical dark energy and modified gravity model alternatives are based on scalar fields. Still, further…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 C. S. C. M. Coelho , A. -L. Y. Gschrey , C. J. A. P. Martins

One of the most compelling goals of observational cosmology is the characterisation of the properties of the dark energy component thought to be responsible for the recent acceleration of the universe, including its possible dynamics. In…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 C. J. A. P. Martins , M. Prat Colomer

A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Shuang-Nan Zhang , Yin-Zhe Ma

The LCDM cosmological model assumes the existence of a small cosmological constant in order to explain the observed accelerating cosmic expansion. Despite the dramatic improvement of the quality of cosmological data during the last decade…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 L. Perivolaropoulos

As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field equations. In order to test such an…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Antonio Enea Romano

The idea of a rapid sign-switching cosmological constant (mirror AdS-dS transition) in the late universe at $z\sim1.7$, known as the $\Lambda_{\rm s}$CDM model, has significantly improved the fit to observational data and provides a…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Özgür Akarsu , Antonio De Felice , Eleonora Di Valentino , Suresh Kumar , Rafael C. Nunes , Emre Özülker , J. Alberto Vazquez , Anita Yadav

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…

Astrophysics · Physics 2010-11-11 Aleksandra Kurek , Marek Szydlowski

In the paper, we consider two models in which dark energy is coupled with either dust matter or dark matter, and discuss the conditions that allow more time for structure formation to take place at high redshifts. These models are expected…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-08 Shulei Cao , Tong-Jie Zhang , Xinya Wang , Tingting Zhang

Despite the broad successes of the flat $\Lambda$CDM model and its fitness to the various cosmological observations, it confronts challenges stemming from anomalies in the measurements of the Hubble constant ($H_0$) and the amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-28 Saeed Pourojaghi , Mohammad Malekjani

$\Lambda$CDM tensions are by definition model dependent; one sees anomalies through the prism of $\Lambda$CDM. Thus, progress towards tension resolution necessitates checking the consistency of the $\Lambda$CDM model to localise missing…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-13 Özgür Akarsu , Eoin Ó Colgáin , Anjan A. Sen , M. M. Sheikh-Jabbari

We compare higher order gravity models to observational constraints from magnitude-redshift supernova data, distance to the last scattering surface of the CMB, and Baryon Acoustic Oscillations. We follow a recently proposed systematic…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jacob Moldenhauer , Mustapha Ishak

We consider nonlinear redshift-dependent equation of state parameters as dark energy models in a spatially flat Friedmann-Lema\^itre-Robertson-Walker universe. To depict the expansion history of the universe in such cosmological scenarios,…

General Relativity and Quantum Cosmology · Physics 2018-02-06 Weiqiang Yang , Supriya Pan , Andronikos Paliathanasis

Bimetric gravity is an interesting alternative to standard GR given its potential to provide a concrete theoretical framework for a ghost-free massive gravity theory. Here we investigate a class of Bimetric gravity models for their…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Ajay Bassi , Shahnawaz A. Adil , Manvendra Pratap Rajvanshi , Anjan A. Sen