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Related papers: Gaussian Process Estimation of Transition Redshift

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The next generation of cosmology experiments will be required to use photometric redshifts rather than spectroscopic redshifts. Obtaining accurate and well-characterized photometric redshift distributions is therefore critical for Euclid,…

Instrumentation and Methods for Astrophysics · Physics 2025-06-03 Ibrahim A. Almosallam , Matt J. Jarvis , Stephen J. Roberts

Much focus was on the possible slowing down of cosmic acceleration under the dark energy parametrization. In the present paper, we investigate this subject using the Gaussian processes (GP), without resorting to a particular template of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-07 Ming-Jian Zhang , Jun-Qing Xia

Using the 37-point cosmic-chronometer subset of observational Hubble parameter (OHD) data, we develop a Bayesian Gaussian-process framework to reconstruct the normalized dark-energy density \(f(z)\) and equation of state \(w(z)\), focusing…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-14 Jia-yan Jiang , Wei Hong , Tong-jie Zhang

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

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.…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Salvatore Capozziello , Orlando Luongo

We apply Gaussian processes (GP) in order to impose constraints on teleparallel gravity and its $f(T)$ extensions. We use available $H(z)$ observations from (i) cosmic chronometers data (CC); (ii) Supernova Type Ia (SN) data from the…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Rebecca Briffa , Salvatore Capozziello , Jackson Levi Said , Jurgen Mifsud , Emmanuel N. Saridakis

The deceleration parameter q as the diagnostic of the cosmological accelerating expansion is investigated. By expanding the luminosity distance to the fourth order of redshift and the so-called y-redshift in two redshift bins and fitting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ronggen Cai , Zhongliang Tuo

We present a determination of the Hubble constant ($H_0$) using the latest observational data from multiple cosmological probes, providing an independent geometric calibration of the SN Ia distance scale. By combining baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-06 Tonghua Liu , Shuo Cao , Jieci Wang

The apparent magnitude-redshift data of SNe Ia call for modifications in the standard model energy densities. Under the circumstance that this modification cannot be limited to the addition of a mere cosmological constant, a serious…

Astrophysics · Physics 2009-12-30 Moncy V. John

Alternative cosmological models have been proposed to alleviate the tensions reported in the concordance cosmological model, or to explain the current accelerated phase of the universe. One way to distinguish between General Relativity and…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-11 Fernanda Oliveira , Felipe Avila , Armando Bernui , Alexander Bonilla , Rafael C. Nunes

Recent cosmological observations have achieved high-precision measurements of the Universe's expansion history, prompting the use of nonparametric methods such as Gaussian processes (GP) regression. We apply GP regression for reconstructing…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-21 Jia-yan Jiang , Kang Jiao , Tong-Jie Zhang

By using recent $H(z)$ and SNe Ia data, we reconstruct the evolution of kinematic parameters $H(z)$, $q(z)$, jerk and snap, using a model-independent, non-parametric method, namely, the Gaussian Processes. Throughout the present analysis,…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-29 J. F. Jesus , D. Benndorf , S. H. Pereira , A. A. Escobal

The motivation of this paper is to obtain reliable constraints of transition redshift ($z_{ztr}$) and, in combination with the evolution of the Hubble constant ($H_{0}$) that could alleviate the Hubble tension, discuss the possible origin…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-08 Jianping Hu , Xuandong Jia , DaoHong Gao , Jiaze Gao , Baoquan Gao , Fayin Wang

Kernel-based machine learning approaches are gaining increasing interest for exploring and modeling large dataset in recent years. Gaussian process (GP) is one example of such kernel-based approaches, which can provide very good performance…

Machine Learning · Computer Science 2019-07-09 Yuxin Zhao , Feng Yin , Fredrik Gunnarsson , Fredrik Hultkrantz

The use of Gaussian Processes with a measurement of the cosmic expansion rate based solely on the observation of cosmic chronometers provides a completely cosmology-independent reconstruction of the Hubble constant H(z) suitable for testing…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Fulvio Melia , Manoj K. Yennapureddy

We constrain the deceleration-acceleration epoch, namely the transition redshift $z_{tr}$, adopting model-independent techniques that utilize a calibrated $E_{\rm p}$-$E_{\rm iso}$ correlation for gamma-ray bursts (GRBs). To do so, in…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-30 Marco Muccino , Orlando Luongo , Deepak Jain

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…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-01 Anna Chiara Alfano , Salvatore Capozziello , Orlando Luongo , Marco Muccino

Accurate photometric redshifts are a lynchpin for many future experiments to pin down the cosmological model and for studies of galaxy evolution. In this study, a novel sparse regression framework for photometric redshift estimation is…

Instrumentation and Methods for Astrophysics · Physics 2025-06-03 Ibrahim A. Almosallam , Sam N. Lindsay , Matt J. Jarvis , Stephen J. Roberts

We examine the observational viability of a class of $f(\mathcal{R})$ gravity cosmological models. Particular attention is devoted to constraints from the recent observational determination of the redshift of the cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Salvatore Capozziello , Omer Farooq , Orlando Luongo , Bharat Ratra

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