English
Related papers

Related papers: Exploring Universe acceleration through observatio…

200 papers

Galaxy surveys map the three-dimensional distribution of matter in the Universe, encoding information about both the primordial cosmos and its subsequent evolution. By comparing the angular and physical scales of features in the galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-16 Mikhail M. Ivanov , Oliver H. E. Philcox

We propose two model independent methods to obtain constraints on the transition and equivalence redshifts $z_{tr}$, $z_{eq}$. In particular, we consider $z_{tr}$ as the onset of cosmic acceleration, whereas $z_{eq}$ the redshift at which…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Salvatore Capozziello , Peter K. S. Dunsby , Orlando Luongo

We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Vincenzo Vitagliano , Jun-Qing Xia , Stefano Liberati , Matteo Viel

In the present work we discuss a third alternative to explain the latest observational data concerning the accelerating Universe and its different stages. The particle creation mechanism in the framework of non-equilibrium thermodynamics is…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Subenoy Chakraborty , Supriya Pan , Subhajit Saha

The present work is based on the holographic dark energy model with Hubble horizon as the infrared cut-off. The interaction rate between dark energy and dark matter has been reconstructed for three different parameterizations of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-28 Ankan Mukherjee

We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal LCDM model. We show that independent determinations of the Hubble…

Astrophysics · Physics 2014-11-18 Daniel G. Figueroa , Licia Verde , Raul Jimenez

Measurement of the universe expansion rate through the cosmic chronometers proves to be a novel approach to understanding cosmic history. Although it provides a direct determination of the Hubble parameters at different redshifts, it…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-12 Faeze Jalilvand , Ahmad Mehrabi

We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 < z < 2.3 and use this to place constraints on model parameters of constant and time-evolving dark energy cosmologies. These H(z) measurements…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Omer Farooq , Bharat Ratra

We use 21 Hubble parameter versus redshift data points, from Gazta\~{n}aga et al. (2009), Stern et al. (2010), and Moresco et al. (2012), to place constraints on model parameters of constant and time-evolving dark energy cosmologies. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Omer Farooq , Data Mania , Bharat Ratra

An accurate determination of the Hubble constant remains a puzzle in observational cosmology. The possibility of a new physics has emerged with a significant tension between the current expansion rate of our Universe measured from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , G. Pordeus-da-Silva , S. H. Pereira

We propose a new parametrization of the deceleration parameter to study its time-variation behavior. The advantage of parameterizing the deceleration parameter is that we do not need to assume any underlying theory of gravity. By fitting…

Astrophysics · Physics 2008-11-26 Yungui Gong , Anzhong Wang

Nowadays, efforts are being devoted to the study of alternative cosmological scenarios in which modifications of General Relativity have been proposed to explain the late cosmic acceleration without assuming the existence of dark energy. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-17 Bruno Ribeiro , Armando Bernui , Marcela Campista

The 21-cm power spectrum of reionization is a promising probe for cosmology and fundamental physics. Exploiting this new observable, however, requires fast predictors capable of efficiently scanning the very large parameter space of…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Aurel Schneider , Timothée Schaeffer , Sambit K. Giri

We generalise the procedure for joint estimation of cosmological parameters to allow freedom in the relative weights of various probes. This is done by including in the joint Likelihood function a set of 'Hyper-Parameters', which are dealt…

Astrophysics · Physics 2007-05-23 Ofer Lahav

Confirmation of accelerated expansion of the universe probed the concept of dark energy theory, and since then, numerous models have been introduced to explain its origin and nature. The present work is based on reconstructing dark energy…

General Relativity and Quantum Cosmology · Physics 2023-10-09 Himanshu Chaudhary , Amine Bouali , Ujjal Debnath , Tanusree Roy , G. Mustafa

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

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

In this letter, we study the cosmological dynamics of steeper potential than exponential. Our analysis shows that a simple extension of an exponential potential allows to capture late-time cosmic acceleration and retain the tracker…

General Relativity and Quantum Cosmology · Physics 2018-02-02 M. Shahalam , Weiqiang Yang , R. Myrzakulov , Anzhong Wang

Recently, the vacuum energy of the QCD ghost in a time-dependent background is proposed as a kind of dark energy candidate to explain the acceleration of the universe. In this model, the energy density of the dark energy is proportional to…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-22 Chao-Jun Feng , Xin-Zhou Li , Xian-Yong Shen

We present a new model based on General Relativity in where a subtle change of curvature at late times is able to produce the observed Universe acceleration and an oscillating behavior in the effective equation of state. This model aims to…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-18 A. Esteban-Gutiérrez , Miguel A. García-Aspeitia , A. Hernández-Almada , Juan Magaña , V. Motta