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Related papers: Cosmographic parameters in model-independent appro…

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By using the supernovae type Ia data we study influence of the anisotropy (although low) on the evolution of the universe and compare ${\Lambda}$CDM model with 6 representative parametrizations of the recent Hubble expansion history $H(z)$.…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-05 H. Hossienkhani , H. Yousefi , N. Azimi

In this paper, a parametrization describing the kinematical state of the universe via cosmographic approach is considered, where the minimum input is the assumption of the cosmological principle, i.e. the Friedmann-Robertson-Walker metric.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Lixin Xu , Yuting Wang

In the era of precision cosmology, even percentage level effects are significant on cosmological observables. The recent tension between the local and global values of $H_0$ is much more significant than this, and any possible solution…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Alan A. Coley , Beethoven Santos , Viraj A A Sanghai

Recent cosmological tensions, in particular, to infer the local value of the Hubble constant $H_0$, have developed new independent techniques to constrain cosmological parameters in several cosmologies. Moreover, even when the concordance…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-14 Pablo M. Maldonado Alonso , Celia Escamilla-Rivera , Rodrigo Sandoval-Orozco

(abridged)Cosmological observational programs often compare their data not only with $\Lambda$CDM, but also with extensions applying dynamical models of dark energy (DDE), with a time-dependent equation of state (EoS) parameter $w$. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-13 Horst Foidl , Tanja Rindler-Daller

The Hubble crisis is the discrepancy in the values of the Hubble constant inferred from diverse observations in the late and early Universe, being of the order 5$\sigma$. Instead of resolution, the conflict is getting larger with further…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-29 Furkan Şakir Dilsiz , Cemsinan Deliduman , Selinay Sude Binici

The mismatch between the locally measured expansion rate of the universe and the one inferred from the cosmic microwave background measurements by Planck in the context of the standard $\Lambda$CDM, known as the Hubble tension, has become…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-11 Karsten Jedamzik , Levon Pogosian , Gong-Bo Zhao

Direct measurements of Hubble parameters $H(z)$ are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Xiaogang Zheng , Marek Biesiada , Xuheng Ding , Shuo Cao , Sixuan Zhang , Zong-Hong Zhu

The standard cosmological model, the $\Lambda$CDM model, is the most suitable description for our universe. This framework can explain the accelerated expansion phase of the universe but still is not immune to open problems when it comes to…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-01 Maria Giovanna Dainotti , Biagio De Simone , Giovanni Montani , Malgorzata Bogdan

The cosmological principle states that the Universe is statistically homogeneous and isotropic at large distance scales. There currently exist many observations which indicate a departure from this principle. It has been shown that many of…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-31 Shamik Ghosh , Pankaj Jain , Rahul Kothari , Mohit Panwar , Gurmeet Singh , Prabhakar Tiwari

We review a subset of the current tensions affecting the standard $\Lambda$CDM cosmological model, emphasizing the role of chronic systematics and significance inflation in shaping their interpretation. As a unifying framework, we consider…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Valerio Marra

CMB anisotropy data could put powerful constraints on theories of the evolution of our Universe. Using the observations of the large number of CMB experiments, many studies have put constraints on cosmological parameters assuming different…

Astrophysics · Physics 2015-06-24 Marian Douspis

Cosmography provides a direct method to map the expansion history of the Universe in a model-independent way. Recently, different kinds of observations have been used in cosmographic analyses, such as SNe Ia and gamma ray bursts…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-06 R. F. L. Holanda , J. S. Alcaniz , J. C. Carvalho

We test the theoretical predictions of several cosmological models against different observables to compare the indirect estimates of the current expansion rate of the Universe determined from model fitting with the direct measurements…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 Vladimir V. Luković , Rocco D'Agostino , Nicola Vittorio

This paper is based on two insights: (1) that general relativity alone does not specify how much of the matter density contributes to the source term in Friedmann's equation, and how much contributes as the source of the gravitational…

General Relativity and Quantum Cosmology · Physics 2024-04-23 Richard J. Cook

In the framework of renormalization-group improved cosmologies, we analyze both theoretically and observationally the exact and general solution of the matter-dominated cosmological equations, using the expression of \Lambda = \Lambda(G)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Ester Piedipalumbo , Paolo Scudellaro , Giampiero Esposito , Claudio Rubano

To probe the late evolution history of the Universe, we adopt two kinds of optimal basis systems. One of them is constructed by performing the principle component analysis (PCA) and the other is build by taking the multidimensional scaling…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-08 Chao-Jun Feng , Xin-Zhou Li

The concordance (LambdaCDM) model reproduces the main current cosmological observations assuming the validity of general relativity at all scales and epochs, the presence of cold dark matter, and of a cosmological constant, equivalent to a…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-08 Guido Risaliti , Elisabeta Lusso

The difference from 4 to 6 $\sigma$ in the Hubble constant ($H_0$) between the values observed with the local (Cepheids and Supernovae Ia, SNe Ia) and the high-z probes (CMB obtained by the Planck data) still challenges the astrophysics and…

Over twenty years ago, Type Ia Supernovae (SNIa) observations revealed an accelerating Universe expansion, suggesting a significant dark energy presence, often modelled as a cosmological constant, \( \Lambda \). Despite its pivotal role in…