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相关论文: Reconstruction of the Cosmic Equation of State for…

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The understanding of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. Whether or not the acceleration is driven by some form of dark energy, and in the absence of a…

宇宙学与河外天体物理 · 物理学 2015-06-17 E. Piedipalumbo , E. Della Moglie , M. De Laurentis , P. Scudellaro

We reconstruct the Equation of State of Dark Energy (EoS) from current data using a non-parametric approach where, rather than assuming a specific time evolution of this function, we bin it in time. We treat the transition between the bins…

宇宙学与河外天体物理 · 物理学 2019-08-23 Francesca Gerardi , Matteo Martinelli , Alessandra Silvestri

The explanation of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. If the acceleration is driven by some form of dark energy, one can try to constrain the parameters…

宇宙学与河外天体物理 · 物理学 2015-06-05 Marek Demianski , Ester Piedipalumbo , Claudio Rubano , Paolo Scudellaro

We study the dark energy equation of state as a function of redshift in a non-parametric way, without imposing any {\it a priori} $w(z)$ (ratio of pressure over energy density) functional form. As a check of the method, we test our scheme…

宇宙学与河外天体物理 · 物理学 2014-03-05 Sergey Postnikov , Maria Giovanna Dainotti , Xavier Hernandez , Salvatore Capozziello

Several independent cosmological data, collected within the last twenty years, revealed the accelerated expansion rate of the Universe, usually assumed to be driven by the so called dark energy, which, according to recent estimates,…

宇宙学与河外天体物理 · 物理学 2020-10-16 Marek Demianski , Elisabeta Lusso , Maurizio Paolillo , Ester Piedipalumbo , Guido Risaliti

A possible method to reconstruct the cosmic equation of state using strong gravitational lensing systems is proposed. The feasibility of the method is investigated by carrying out the reconstruction on the basis of a simple Monte-Carlo…

天体物理学 · 物理学 2009-11-06 Kazuhiro Yamamoto , Toshifumi Futamase

The current accelerated expansion of the Universe remains ones of the most intriguing topics in modern cosmology, driving the search for innovative statistical techniques. Recent advancements in machine learning have significantly enhanced…

宇宙学与河外天体物理 · 物理学 2025-01-03 José de Jesús Velázquez , Luis A. Escamilla , Purba Mukherjee , J. Alberto Vázquez

In this study, we introduce a novel late-time effective dark energy model characterized by a quadratic equation of state (EoS) and rigorously examine its observational constraints. Initially, we delve into the background dynamics of this…

宇宙学与河外天体物理 · 物理学 2024-06-11 Hossein Moshafi , Alireza Talebian , Ebrahim Yusofi , Eleonora Di Valentino

Since the late 1990's observations of type Ia Supernova, our universe is predicted to experience a late time cosmic acceleration. Theoretical support to this observation were intended to be built via proposition of a hypothetical fluid…

广义相对论与量子宇宙学 · 物理学 2020-08-10 Promila Biswas , Parthajit Roy , Ritabrata Biswas

For the first time, we reconstruct the dark energy equation of the state parameter $w$ from the combination of background and perturbation observations, specifically combining the Hubble parameter data from cosmic chronometer observations…

宇宙学与河外天体物理 · 物理学 2024-07-15 Bikash R. Dinda , Narayan Banerjee

We use the HII galaxies $L - \sigma$ relation and the resulting Hubble expansion cosmological probe of a sample of just 25 high-$z$ (up to $z \sim 2.33$) HII galaxies, in a joint likelihood analysis with other well tested cosmological…

We apply two methods, namely the Gaussian processes and the non-parametric smoothing procedure, to reconstruct the Hubble parameter $H(z)$ as a function of redshift from 15 measurements of the expansion rate obtained from age estimates of…

宇宙学与河外天体物理 · 物理学 2016-03-02 Zhengxiang Li , J. E. Gonzalez , Hongwei Yu , Zong-Hong Zhu , J. S. Alcaniz

The equation of state (EoS) of dark energy plays an important role in the evolution of the universe and arouses great interests in recent years. With the progress on observational technique, precise constraint on the EoS of dark energy…

广义相对论与量子宇宙学 · 物理学 2019-08-19 Hai-Nan Lin , Xin Li , Li Tang

In this article, the bulk viscosity is introduced in a modified gravity model. The gravitational action has a general $f(R,T)$ form, where $R$ and $ T $ are the curvature scalar and the trace of energy momentum tensor respectively. An…

广义相对论与量子宇宙学 · 物理学 2020-10-02 Simran Arora , Xin-he Meng , S. K. J. Pacif , P. K. Sahoo

Non-parametric reconstruction of the dark energy equation of state (EoS) aims to determine the EoS as a function of redshift without invoking any particular dark energy model, so that the resulting EoS can be free of model-induced biases or…

宇宙学与河外天体物理 · 物理学 2019-10-09 Youhua Xu , Hu Zhan , Yeuk-Kwan Edna Cheung

We develop a method for implementing a proposal on utilizing knowledge of neutron star (NS) equation of state (EoS) for inferring the Hubble constant from a population of binary neutron star (BNS) mergers. This method is useful in…

宇宙学与河外天体物理 · 物理学 2023-01-03 Tathagata Ghosh , Bhaskar Biswas , Sukanta Bose

The present work is based upon a parametric reconstruction of the effective or total equation of state in a model for the universe with accelerated expansion. The constraints on the model parameters are obtained by maximum likelihood…

宇宙学与河外天体物理 · 物理学 2016-05-27 Ankan Mukherjee

This paper constraints dynamic dark energy equation of state (EoS) parameters using the type Ia supernovae from Union 2.1 dataset. The paper also discusses the dependency of dynamic dark energy EoS parameters on the chosen or assumed value…

宇宙学与河外天体物理 · 物理学 2020-09-30 Syed Faisal ur Rahman

The standard relation between the cosmological redshift and cosmic scale factor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the LambdaCDM cosmological model. This…

宇宙学与河外天体物理 · 物理学 2019-08-08 Radosław Wojtak , Francisco Prada

In this paper, we firstly calibrate the Amati relation (the $E_{\rm p}-E_{\rm iso}$ correlation) of gamma ray bursts (GRBs) at low redshifts ($z<0.8$) via Gaussian process by using the type Ia supernovae samples from Pantheon+ under the…

宇宙学与河外天体物理 · 物理学 2023-09-12 Yuhao Mu , Baorong Chang , Lixin Xu
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