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We forecast the expected cosmological constraints from a combination of probes of both the universal expansion rate and matter perturbation growth, in the form of weak lensing tomography, galaxy tomography, supernovae, and the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-10 Shahab Joudaki , Manoj Kaplinghat

We further investigate slowing down of acceleration of the universe scenario for five parametrizations of the equation of state of dark energy using four sets of supernovae data. In a maximal probability analysis we also use the baryon…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Juan Magaña , Víctor H. Cárdenas , V. Motta

We study the $\Lambda(\alpha)$CDM models with $\Lambda(\alpha)$ being a function of the time-varying fine structure constant $\alpha$. We give a close look at the constraints on two specific $\Lambda(\alpha)$CDM models with one and two…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-13 Jin-Jun Zhang , Lu Yin , Chao-Qiang Geng

Despite the interest in dark matter and dark energy, it has never been shown that they are in fact two separate substances. We provide the first strong evidence that they are separate by ruling out a broad class of so-called unified dark…

Astrophysics · Physics 2008-11-26 Havard Sandvik , Max Tegmark , Matias Zaldarriaga , Ioav Waga

In this paper, we constrain four time-dependent dark energy (TDDE) models by using the Type Ia supernovae (SNe Ia), baryonic acoustic oscillations (BAO), observational Hubble parameter (OHD) data-sets as well as the single data point from…

General Relativity and Quantum Cosmology · Physics 2016-03-03 Deng Wang , Xin-He Meng

An impressive amount of different astrophysical data converges towards the picture of a spatially flat universe undergoing a today phase of accelerated expansion. The nature of the dark energy dominating the energy content of the universe…

Astrophysics · Physics 2009-11-10 S. Capozziello , V. F. Cardone , M. Funaro , S. Andreon

Astrophysical observations have put unprecedentedly tight constraints on cosmological theories. The $\Lambda$CDM model, mathematically simple and fits observational data-sets well, is preferred for explaining the behavior of universe. But…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Qiang Zhang , Guang Yang , Qixiang Zou , Xinhe Meng , Keji Shen

The dark energy cosmology with the equation of state $w=constant$ is considered in this paper. The $\Omega_{DE}-\Omega_{M}$ plane has been used to study the present state and expansion history of the universe. Through the mathematical…

Astrophysics · Physics 2009-11-11 Yuan Qiang , Tong-Jie Zhang

Despite the great progress of current cosmological measurements, the nature of the dominant component of the universe, coined dark energy, is still an open question. Early Dark Energy is a possible candidate which may also alleviate some…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-07 Maria Archidiacono , Laura Lopez-Honorez , Olga Mena

We introduce EFTCAMB/EFTCosmoMC as publicly available patches to the commonly used CAMB/CosmoMC codes. We briefly describe the structure of the codes, their applicability and main features. To illustrate the use of these patches, we obtain…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Marco Raveri , Bin Hu , Noemi Frusciante , Alessandra Silvestri

A phenomenological model of dark energy that tracks the baryonic and cold dark matter at early times but resembles a cosmological constant at late times is explored. In the transition between these two regimes, the dark energy density drops…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-13 Jannis Bielefeld , W. L. Kimmy Wu , Robert R. Caldwell , Olivier Dore

We constrain and compare the $w_{0}w_{a}$CDM dynamical dark energy model and three $f(R)$ modified gravity models using the current cosmological distance measurements, including 112 high-quality localized FRBs, BAO measurements from the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-24 Shuai Feng , Yan Gong , Xiaohui Liu , Jun-Hui Yan , Xuelei Chen

In the context of cosmography approach and using the data of Hubble diagram for supernovae, quasars and gamma-ray bursts, we study some DE parametrizations and also the concordance $\Lambda$CDM universe. Using the different combinations of…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-09 Mehdi Rezaei , Saeed Pour Ojaghi , Mohammad Malekjani

In the standard model of cosmology, dark matter and dark energy are presently the two main contributors to the total energy in the Universe. However, these two dark components are still of unknown nature, and many alternative explanations…

Astrophysics · Physics 2009-06-25 A. Arbey

Driven by the CMB temperature-redshift ($T$-$z$) relation as demanded by deconfining SU(2) Yang-Mills thermodynamics, an according cosmological model is proposed and analysed. This model -- SU(2)$_\CMB$ -- exhibits a dark sector,…

General Physics · Physics 2018-12-13 Steffen Hahn , Ralf Hofmann , Daniel Kramer

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

In this paper, we study several models and parameterizations of dynamical dark energy (DE) that have been studied already in the past, in conjunction with the recently proposed model $w$XCDM, the running vacuum model (RVM) with and without…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-03 Javier de Cruz Pérez , Adrià Gómez-Valent , Joan Solà Peracaula

We study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…

Astrophysics · Physics 2011-07-19 Silviu Podariu , Bharat Ratra

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

The oscillating scenario of route to Lambda was recently proposed by us arXiv:0704.1651 as an alternative to a cosmological constant in a explanation of the current accelerating universe. In this scenario phantom scalar field conformally…

Astrophysics · Physics 2008-11-26 Aleksandra Kurek , Orest Hrycyna , Marek Szydlowski
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