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This paper aims to put constraints on the transition redshift $z_t$, which determines the onset of cosmic acceleration, in cosmological-model independent frameworks. In order to perform our analyses, we consider a flat universe and {assume}…

宇宙学与河外天体物理 · 物理学 2018-05-31 J. F. Jesus , R. F. L. Holanda , S. H. Pereira

We consider a model-independent approach to constrain the equivalence redshift, $z_{eq}$, at which dark energy and the total matter (cold dark matter and baryonic) equate their magnitudes. To this aim, in the context of a homogeneous and…

宇宙学与河外天体物理 · 物理学 2023-08-31 Anna Chiara Alfano , Carlo Cafaro , Salvatore Capozziello , Orlando Luongo

Directly comparing the 6 expansion rate measured by type Ia supernovae data and the lower bound on the expansion rate set by the strong energy conditions or the null hypothesis that there never exists cosmic acceleration, we see $3\sigma$…

宇宙学与河外天体物理 · 物理学 2020-07-06 Yingjie Yang , Yungui Gong

We revisit the epoch of cosmic speed-up characterized by the redshift of transition from a decelerated to an accelerated phase. This redshift is termed the transition redshift ($z_t$). We use the spatially Flat and Non-Flat variants of the…

宇宙学与河外天体物理 · 物理学 2023-08-02 David Dahiya , Deepak Jain

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…

宇宙学与河外天体物理 · 物理学 2012-04-22 J. C. Carvalho , J. S. Alcaniz

One of the most significant discoveries in modern cosmology is that the universe is currently in a phase of accelerated expansion after a switch from a decelerated expansion. The redshift corresponding to this epoch is referred to as the…

宇宙学与河外天体物理 · 物理学 2023-05-18 Darshan Kumar , Deepak Jain , Shobhit Mahajan , Amitabha Mukherjee , Akshay Rana

Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae and Baryon Acoustic Oscillations, providing evidence for the existence of…

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…

宇宙学与河外天体物理 · 物理学 2015-06-12 Omer Farooq , Bharat Ratra

The redshift $z_t$ and the jerk parameter $j_t$ of the transition epoch are constrained by using two model-independent approaches involving the direct expansion of the Hubble rate and the expansion of the deceleration parameter around…

宇宙学与河外天体物理 · 物理学 2024-03-01 Anna Chiara Alfano , Salvatore Capozziello , Orlando Luongo , Marco Muccino

We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

宇宙学与河外天体物理 · 物理学 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

We propose a strategy to infer the transition redshift $z_{da}$, which characterizes the passage through the universe decelerated to accelerated phases, in the framework $f(R)$ gravities. To this end, we numerically reconstruct $f(z)$, i.e.…

宇宙学与河外天体物理 · 物理学 2014-11-11 Salvatore Capozziello , Orlando Luongo

This paper aims to put constraints on the transition redshift $z_t$, which determines the onset of cosmic acceleration, in cosmological-model independent frameworks. In order to do that, we use the non-parametric Gaussian Process method…

宇宙学与河外天体物理 · 物理学 2020-05-20 J. F. Jesus , R. Valentim , A. A. Escobal , S. H. Pereira

Knowing the late time evolution of the Universe and finding out the causes for this evolution are the important challenges of modern cosmology. In this work, we adopt a model-independent cosmographic approach and approximate the Hubble…

宇宙学与河外天体物理 · 物理学 2019-01-23 Salvatore Capozziello , Ruchika , Anjan A Sen

In this paper, we use the Cosmokinematics approach to study the accelerated expansion of the Universe. This is a model independent approach and depends only on the assumption that the Universe is homogeneous and isotropic and is described…

广义相对论与量子宇宙学 · 物理学 2016-01-06 Nisha Rani , Deepak Jain , Shobhit Mahajan , Amitabha Mukherjee , Nilza Pires

We propose a model-independent formalism to numerically solve the modified Friedmann equations in the framework of $f(T)$ teleparallel cosmology. Our strategy is to expand the Hubble parameter around the redshift $z=0$ up to a given order…

广义相对论与量子宇宙学 · 物理学 2017-11-01 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

The expansion rate of the Universe changes with time, initially slowing (decelerating) when the universe was matter dominated, because of the mutual gravitational attraction of all the matter in it, and more recently speeding up…

宇宙学与河外天体物理 · 物理学 2013-09-17 Muhammad Omer Farooq

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

广义相对论与量子宇宙学 · 物理学 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin

We extract constraints on the transition redshift $z_{tr}$, determining the onset of cosmic acceleration, predicted by an effective cosmographic construction, in the framework of $f(T)$ gravity. In particular, employing cosmography we…

广义相对论与量子宇宙学 · 物理学 2015-06-19 Salvatore Capozziello , Orlando Luongo , Emmanuel N. Saridakis

Here we test different models of dark energy beyond the standard cosmological constant scenario. We start considering the CPL parameterization of the equation of state (EOS), then we consider a dark energy scalar field (Quintessense).…

高能天体物理现象 · 物理学 2018-02-07 Marek Demianski , Ester Piedipalumbo , Disha Sawant , Lorenzo Amati

We perform a model-independent investigation of the thermodynamic evolution of the Universe by reconstructing the expansion history from observational data using Gaussian Process regression. We consider three independent combinations of…

宇宙学与河外天体物理 · 物理学 2026-04-22 Afaq Maqsood , Tanima Duary
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