English
Related papers

Related papers: Cosmographic parameters in model-independent appro…

200 papers

We discussed the dynamics of cosmological models in which the cosmological constant term is a time dependent function through the scale factor $a(t)$, Hubble function $H(t)$, Ricci scalar $R(t)$ and scalar field $\phi(t)$. We considered…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-29 Aleksander Stachowski , Marek Szydlowski

We study the reconstructed deceleration parameter splitting the data in different redshift bins, fitting both a cosmographic luminosity distance and also assuming a flat $\Lambda$CDM model, using the Pantheon+ sample of type Ia supernova…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Erick Pastén , Victor Cárdenas

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-02 Zhengxiang Li , J. E. Gonzalez , Hongwei Yu , Zong-Hong Zhu , J. S. Alcaniz

We perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets. We pay particular attention to the influence of both statistical and systematic uncertainties, and also to the extent to which the choice…

General Relativity and Quantum Cosmology · Physics 2007-07-31 Celine Cattoen , Matt Visser

A cosmographic reconstruction of $f(\mathcal T)$ models is here revised in a model independent way by fixing observational bounds on the most relevant terms of the $f(\mathcal T)$ Taylor expansion. We relate the $f(\mathcal T)$ models and…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Alejandro Aviles , Alessandro Bravetti , Salvatore Capozziello , Orlando Luongo

Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Lloyd Knox , Marius Millea

The $\Lambda$CDM model provides a good fit to a large span of cosmological data but harbors areas of phenomenology. With the improvement of the number and the accuracy of observations, discrepancies among key cosmological parameters of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Eleonora Di Valentino , Olga Mena , Supriya Pan , Luca Visinelli , Weiqiang Yang , Alessandro Melchiorri , David F. Mota , Adam G. Riess , Joseph Silk

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

We propose an analytical parametrization of the comoving distance and Hubble parameter to study the cosmic expansion history beyond the vanilla $\Lambda$CDM model. The parametrization is generalized enough to include the contribution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-22 Bikash R. Dinda

We study the possibility to extract model independent information about the dynamics of the universe by using Cosmography. We intend to explore it systematically, to learn about its limitations and its real possibilities. Here we are…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Salvatore Capozziello , Ruth Lazkoz , Vincenzo Salzano

The redshift drift provides a kinematic test of the cosmic expansion history through the slow time variation of the redshift of comoving sources. Motivated by the expected Sandage-Loeb measurements from future facilities, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-06 Anna Chiara Alfano , Orlando Luongo

In this paper, linear first order expansion of deceleration parameter $q(z)=q_0+q_1(1-a)$ ($M_1$), constant jerk $j=j_0$ ($M_2$) and third order expansion of luminosity distance ($M_3$) are confronted with cosmic observations: SCP 307 SN…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-24 Lixin Xu , Wenbo Li , Jianbo Lu

Cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way. In this paper, we first investigate the effect of the ultraviolet (UV) and X-ray relation of a quasar on…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 J. P. Hu , F. Y. Wang

Cosmography, as an integral branch of cosmology, strives to characterize the Universe without relying on pre-determined cosmological models. This model-independent approach utilizes Taylor series expansions around the current epoch,…

General Physics · Physics 2024-06-11 Seokcheon Lee

The mismatch between different independent measurements of the expansion rate of the Universe is known as the Hubble constant ($H_0$) tension, and it is a serious and pressing problem in cosmology. We investigate this tension considering…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-17 Tiziano Schiavone , Giovanni Montani , Maria Giovanna Dainotti , Biagio De Simone , Enrico Rinaldi , Gaetano Lambiase

In this work, we present independent determinations of cosmological parameters and new constraints on $f(T)$ cosmologies, employing two new catalogs related to HII galaxy Hubble and CMB distance priors, along with the local standard…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Rodrigo Sandoval-Orozco , Celia Escamilla-Rivera , Rebecca Briffa , Jackson Levi Said

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 study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…

Astrophysics · Physics 2011-07-19 Silviu Podariu , Bharat Ratra

The standard model of cosmology, the $\Lambda$CDM model, describes the evolution of the Universe since the Big Bang with just a few parameters, six in its basic form. Despite being the simplest model, direct late-time measurements of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Lavinia Heisenberg , Hector Villarrubia-Rojo

The $\Lambda$CDM model provides a good fit to most astronomical observations but harbors large areas of phenomenology and ignorance. With the improvements in the precision and number of observations, discrepancies between key cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Jian-Ping Hu , Fa-Yin Wang