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Related papers: Curvature vs Distances: testing the FLRW cosmology

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The cosmic curvature ($\Omega_k$) is a fundamental parameter for cosmology. In this paper, we propose an improved model-independent method to constrain the cosmic curvature, which is geometrically related to the Hubble parameter $H(z)$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Yuting Liu , Shuo Cao , Tonghua Liu , Xiaolei Li , Shuaibo Geng , Yujie Lian , Wuzheng Guo

The assumptions of large-scale homogeneity and isotropy underly the familiar Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) metric that appears to be an accurate description of our Universe. In this paper, we propose a new strategy of…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-24 Shuo Cao , Jingzhao Qi , Zhoujian Cao , Marek Biesiada , Jin Li , Yu Pan , Zong-Hong Zhu

In this paper, cosmic distance duality relation is probed without considering any background cosmological model. The only \textit{a priori} assumption is that the Universe is described by the Friedmann-Lema$\hat{i}$tre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2025-01-28 Savita Gahlaut

We investigate some FLRW cosmological models in the context of Metric-Affine $F(R,Q)$ gravity, as proposed in [arXiv:1205.52666]. Here, $R$ and $Q$ are the curvature and nonmetricity scalars using non-special connections, respectively. We…

General Relativity and Quantum Cosmology · Physics 2024-08-16 Dinesh Chandra Maurya , K. Yesmakhanova , R. Myrzakulov , G. Nugmanova

We propose a model-independent way to determine the cosmic curvature using the Hubble parameter $H(z)$ measured with cosmic chronometers and the comoving distance $D(z)$ inferred from HII galaxies. We employ Gaussian processes to smooth the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-18 Jing Zheng , Fulvio Melia , Tong-Jie Zhang

We investigate a spatially flat FLRW cosmological model in the framework of modified gravity described by the function \( f(R, L_m) = \alpha R + L_m^\beta + \gamma \), where \( L_m \) is the matter Lagrangian density. The modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2026-02-05 G. K. Goswami , Anirudh Pradhan , Syamala Krishnannair

We perform a data-driven test of the FLRW metric and the flatness of the Universe, independently of any Dark Energy model, and in light of the latest DESI DR2 results. We use Pantheon+ and DESY5 SNIa data to reconstruct the distance…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-29 Cléa Millard , Benjamin L'Huillier , Marian Douspis

The interpretation of cosmological observations relies on a notion of an average Universe, which is usually considered as the homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker (FLRW) model. However, inhomogeneities may…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-24 Michel-Andrès Breton , Pierre Fleury

In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

We combine model-independent reconstructions of the expansion history from the latest Pantheon supernovae distance modulus compilation and measurements from baryon acoustic oscillation to test some important aspects of the concordance model…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-25 Arman Shafieloo , Benjamin L'Huillier , Alexei A. Starobinsky

With the distance sum rule in the Friedmann-Lema\^{\i}tre-Robertson-Walker metric, model-independent constraints on both the Hubble constant $H_0$ and spatial curvature $\Omega_{K}$ can be obtained using strong lensing time-delay data and…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 Jun-Jie Wei , Fulvio Melia

The cosmic curvature density parameter has been constrained in the present work independent of any background cosmological model. The reconstruction is performed adopting the non-parametric Gaussian Processes (GP). The constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Purba Mukherjee , Narayan Banerjee

In this paper, we present a scheme to investigate the opacity of the Universe in a cosmological-model-independent way, with the combination of current and future available data in gravitational wave (GW) and electromagnetic (EM) domain. In…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-25 Jing-Zhao Qi , Shuo Cao , Yu Pan , Jin Li

The plethora of recent cosmologically relevant data has indicated that our universe is very well fit by a standard Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) model, with $\Omega_{M} \approx 0.27$ and $\Omega_{\Lambda} \approx 0.73$ --…

Astrophysics · Physics 2009-06-23 M. E. Araújo , W. R. Stoeger

The challenging issue of determining the correct $f(R)$ among several possibilities is here revised by means of numerical reconstructions of the modified Friedmann equations around the redshift interval $z\in[0,1]$. Frequently, a severe…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 Liberato Pizza

A model-independent test of the cosmic curvature parameter $\Omega_k$ is very important in cosmology. In order to estimate cosmic curvature from cosmological probes like standard candles, one has to be able to measure the luminosity…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Xiaogang Zheng , Shuo Cao , Yuting Liu , Marek Biesiada , Tonghua Liu , Shuaibo Geng , Yujie Lian , Wuzheng Guo

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-$\alpha$ forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

Discrepancies between distance measurements and $\Lambda$CDM predictions reveal notable features in the distance-redshift relation, possibly suggesting the presence of an evolving dark energy component. Given the central role of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-06 David Camarena , Kylar Greene , John Houghteling , Francis-Yan Cyr-Racine

In recent years, a crisis in the standard cosmology has been caused by inconsistencies in the measurements of some key cosmological parameters, Hubble constant $H_0$ and cosmic curvature parameter $\Omega_K$ for example. It is necessary to…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-17 Meng-Di Cao , Jie Zheng , Jing-Zhao Qi , Xin Zhang , Zong-Hong Zhu

In this paper, we go further and propose a cosmological model-independent approach to simultaneously determine the Hubble constant and cosmic curvature with strong lensing time-delay measurements, without any prior assumptions regarding the…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-19 Tonghua Liu , Shuo Cao , Sixuan Zhang , Chenfa Zheng , Wuzheng Guo