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Related papers: Cosmographic parameters in model-independent appro…

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We present model independent reconstructions of quintessence and the Swampland conjectures (SC) using both Machine Learning (ML) and cosmography. In particular, we demonstrate how the synergies between theoretical analyses and ML can…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Rubén Arjona , Savvas Nesseris

Whereas many measurements in cosmology depend on the use of integrated distances or time, galaxies evolving passively on a time scale much longer than their age difference allow us to determine the expansion rate H(z) solely as a function…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Jun-Jie Wei , Fulvio Melia , Xue-Feng Wu

Using a new sub-sample of observed strong gravitational lens systems, for the first time, we present the equation for the angular diameter distance in the $y$-redshift scenario for cosmography and use it to test the cosmographic parameters.…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Andrés Lizardo , Mario H. Amante , Miguel A. García-Aspeitia , Juan Magaña , V. Motta

Alternative cosmological models have been under deep scrutiny in recent years, aiming to address the main shortcomings of the $\Lambda$CDM model. Moreover, as the accuracy of cosmological surveys improved, new tensions have risen between…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-05 Filippo Bouchè , Salvatore Capozziello , Vincenzo Salzano

Measurements of the $H_0$ and $\sigma_8$ parameters within the standard cosmological model recently highlighted significant statistical tensions between the cosmic microwave background and low-redshift probes, such as local distance ladder,…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-26 Rocco D'Agostino , Rafael C. Nunes

The dynamics of the Universe are revised using high-redshift data from gamma-ray bursts to constrain cosmographic parameters by means of model-independent techniques. Considering samples from four gamma-ray burst correlations and two…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-13 Orlando Luongo , Marco Muccino

We employ Hubble data and Gaussian Processes in order to reconstruct the dynamical connection function in $f(Q)$ cosmology beyond the coincident gauge. In particular, there exist three branches of connections that satisfy the torsionless…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-10 Yuhang Yang , Xin Ren , Bo Wang , Yi-Fu Cai , Emmanuel N. Saridakis

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

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

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

The latest improvements in the scale and calibration of Type Ia supernovae catalogues allow us to constrain the specific nature and evolution of dark energy through its effect on the expansion history of the universe. We present the results…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-05 Toby Lovick , Suhail Dhawan , Will Handley

In this study, we have explored a transitioning cosmological model of universe's expansion in $f(R,\mathcal{L}_{m})$ gravity. The quadratic type of equation of state parameter in the form $\omega=-1 + \alpha (1 + z) + \beta (1 + z)^2$,…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Vinod Kumar Bhardwaj , Saibal Ray

The mass function of cluster-size halos and their redshift distribution are computed for 12 distinct accelerating cosmological scenarios and confronted to the predictions of the conventional flat $\Lambda$CDM model. The comparison with…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 S. Basilakos , M. Plionis , J. A. S. Lima

A model-independent or non-parametric approach for modeling a database has been widely used in cosmology. In these scenarios, the data has been used directly to reconstruct an underlying function. In this work, we introduce a novel…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-19 Ahmad Mehrabi

Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range $0 < z \leqslant 2.36$ to make a cosmological model-independent test of the $\Lambda$CDM model with…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Shu-Lei Cao , Xiao-Wei Duan , Xiao-Lei Meng , Tong-Jie Zhang

We investigate what current cosmological data tells us about the cosmological expansion rate in a model independent way. Specifically, we study if the expansion was decelerating at high redshifts and is accelerating now, without referring…

Astrophysics · Physics 2009-11-13 Edvard Mortsell , Chris Clarkson

Over the past decade, the disparity between the value of the cosmic expansion rate directly determined from measurements of distance and redshift or instead from the standard $\Lambda$CDM cosmological model calibrated by measurements from…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-10 Marc Kamionkowski , Adam G. Riess

In this paper, we study the power-law $f(T)$ model using Hubble diagrams of type Ia supernovae (SNIa), quasars (QSOs), Gamma Ray Bursts (GRBs) and the measurements from baryonic acoustic oscillations (BAO) in the framework of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 M. Sabiee , M. Malekjani , D. Mohammad Zadeh Jassur

We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble…

Astrophysics · Physics 2015-05-13 V. I. Zhdanov , G. Ivashchenko

It is nowadays accepted that the universe is undergoing a phase of accelerated expansion as tested by the Hubble diagram of Type Ia Supernovae (SNeIa) and several LSS observations. Future SNeIa surveys and other probes will make it possible…

Astrophysics · Physics 2009-02-20 S. Capozziello , V. F. Cardone , V. Salzano