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We explore freezing dark energy, where the evolution of the field approaches that of a cosmological constant at late times. We propose two general, two parameter forms to describe the class of freezing field models, in analogy to ones for…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Eric V. Linder

The evolution of dark energy density is a crucial quantity in understanding the nature of dark energy. Often, the quantity is described by the so-called equation of state, that is the ratio of dark energy pressure to its density. In this…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-14 Ahmad Mehrabi , Maryam Vazirnia

This article discusses a dark energy cosmological model in the standard theory of gravity - general relativity with a broad scalar field as a source. Exact solutions of Einstein's field equations are derived by considering a particular form…

General Relativity and Quantum Cosmology · Physics 2022-08-23 S. K. J. Pacif , Simran Arora , P. K. Sahoo

In this paper, we focus on the parametrization of the effective equation of state (EoS) parameter within the framework of $f(Q)$ symmetric teleparallel gravity. Here, the gravitational action is represented by an arbitrary function of the…

General Relativity and Quantum Cosmology · Physics 2023-07-04 A. Mussatayeva , N. Myrzakulov , M. Koussour

Constraining the dark energy equation of state, $w_x(z)$, is one of the main issues of current and future cosmological surveys. In practice, this requires making assumptions about the evolution of $w_x$ with redshift $z$, which can be…

General Relativity and Quantum Cosmology · Physics 2019-07-29 Celia Escamilla-Rivera , Salvatore Capozziello

We examine dark energy models in which a quintessence or a phantom field, $\phi$, rolls near the vicinity of a local minimum or maximum, respectively, of its potential $V(\phi)$. Under the approximation that $(1/V)(dV/d\phi) \ll 1$,…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-09 Sourish Dutta , Emmanuel N. Saridakis , Robert J. Scherrer

We propose a phenomenological generalisation of the standard model with only one extra degree of freedom that parametrises the evolution of a scalar field responsible for the cosmic acceleration. The model also foresees an additional…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 Vitor da Fonseca , Tiago Barreiro , Nelson J. Nunes

In the present work, we have studied the dynamics of accelerating universe considering a simple parametrization of the equation of state parameter in an interacting scenario. In this toy model, the dark energy component is allowed to…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Sangita Goswami , Sudipta Das

We review the current status of cosmological parameters, dark energy and large-scale structure, from a theoretical and observational perspective. We first present the basic cosmological parameters and discuss how they are measured with…

Astrophysics · Physics 2007-05-23 S. E. Deustua , R. Caldwell , P. Garnavich , L. Hui , A. Refregier

In this research, we have reconstructed the extended $f(\mathcal{P})$ cubic gravity and symmetric $f(\mathcal{Q})$ teleparallel gravity from the $(m,n)$-type Barrow Holographic Dark Energy (BHDE) model. We have derived the unknown functions…

General Relativity and Quantum Cosmology · Physics 2025-06-26 Tamal Mukhopadhyay , Banadipa Chakraborty , Anamika Kotal , Ujjal Debnath

Our universe is observed to be accelerating due to the dominant dark energy with negative pressure. The dark energy equation of state (w) holds a key to understanding the ultimate fate of the universe. The cosmic voids behave like bubbles…

Astrophysics · Physics 2011-02-11 Jounghun Lee , Daeseong Park

A new single-dynamical-scalar-field model of dark energy is proposed, in which either higher derivative terms nor structures of extra dimension are needed. With the help of a fixed background vector field, the parameter for the effective…

Astrophysics · Physics 2007-05-23 Chao-Guang Huang , Han-Ying Guo

In this paper, we propose a new parametrization of dark energy based on the $Om(z)$ diagnostic tool behavior. For this purpose, we investigate a functional form of the $Om(z)$ that predicts the popular dark energy dynamical models, namely…

General Relativity and Quantum Cosmology · Physics 2023-07-13 N. Myrzakulov , M. Koussour , Dhruba Jyoti Gogoi

We investigate the prospects for determining the accelerating history of the Universe from upcoming measurements of the expansion rate $H(z)$. In our analyses, we use Monte Carlo simulations based on $w$CDM models to generate samples with…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-22 J. C. Carvalho , J. S. Alcaniz

A six parameter cosmological model, involving a vacuum energy density that is extremely tiny compared to fundamental particle physics scales, describes a large body of increasingly accurate astronomical data. In a first part of this brief…

High Energy Physics - Phenomenology · Physics 2009-11-11 Norbert Straumann

We baseline with current cosmological observations to forecast the power of the Dark Energy Spectroscopic Instrument (DESI) in two ways: 1. the gain in constraining power of parameter combinations in the standard $\Lambda$CDM model, and 2.…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Samuel Goldstein , Minsu Park , Marco Raveri , Bhuvnesh Jain , Lado Samushia

We present a novel reconstruction method of $f(T)$ teleparallel gravity from phenomenological parameterizations of the deceleration parameter or other alternatives. This can be used as a toolkit to produce viable modified gravity scenarios…

General Relativity and Quantum Cosmology · Physics 2019-10-29 W. El Hanafy , G. G. L. Nashed

In this manuscript, we present a novel dark energy model to study the nature of dark energy. Non-extensive Kaniadakis entropy and, timescale as infrared cutoff are the major tools of the current study. Age of the Universe will serve the…

General Physics · Physics 2022-05-09 Suresh Kumar P , Bramha Dutta Pandey , Pankaj , Umesh Kumar Sharma

The acceleration of the expansion of the universe arises from unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. It is crucial for our understanding to characterize the…

Astrophysics · Physics 2009-11-10 Eric V. Linder

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
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