English
Related papers

Related papers: Data-driven and Almost Model-independent Reconstru…

200 papers

In this paper, we explore modified gravity in the framework of $f(R, \mathcal{L}_m)$ theories by reconstructing the function $f(\mathcal{L}_m)$, where $\mathcal{L}_m = \rho$ is the matter Lagrangian, under the assumption of a pressureless,…

General Relativity and Quantum Cosmology · Physics 2025-06-12 Y. Kalpana Devi , S. A. Narawade , B. Mishra

The aim of this paper is to constrain modified gravity with redshift space distortion observations and supernovae measurements. Compared with a standard LCDM analysis, we include three additional free parameters, namely the initial…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-28 Laura Taddei , Matteo Martinelli , Luca Amendola

In this work we extend our earlier phenomenological model for a gravitational phase transition (GPT) and its generalization to early times by letting the modifications in the linearly-perturbed Einstein equations be scale-dependent. These…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-27 Marzieh Farhang , Nima Khosravi

In light of the statistical performance of cosmological observations, in this work we present an improvement on the Gaussian reconstruction of the Hubble parameter data $H(z)$ from Cosmic Chronometers, Supernovae Type Ia and Clustering…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-28 Mauricio Reyes , Celia Escamilla-Rivera

Adding to our previous method for dealing with gravitational modifications at redshift $z\gtrsim3$ through a single parameter, we investigate treatment of lower redshift modifications to linear growth observables. We establish subpercent…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-29 Mikhail Denissenya , Eric V. Linder

We use a combination of observational data in order to reconstruct the free function of f(T) gravity in a model-independent manner. Starting from the data-driven determined dark-energy equation-of-state parameter we are able to reconstruct…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-20 Xin Ren , Thomas Hong Tsun Wong , Yi-Fu Cai , Emmanuel N. Saridakis

Using redshift space distortion data, we perform model-independent reconstructions of the growth history of matter inhomogeneity in the expanding Universe using two methods: crossing statistics and Gaussian processes. We then reconstruct…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-08 Benjamin L'Huillier , Arman Shafieloo , David Polarski , Alexei A. Starobinsky

The reconstruction scheme is developed for modified $f(R)$ gravity with realistic matter (dark matter, baryons, radiation). Two versions of such theory are constructed: the first one describes the sequence of radiation and matter…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

A reconstruction of modified gravity is proposed by establishing a correspondence between the effective density of the modified gravity and the holographic density. The non-homogeneous term in the modified Friedmann equation, generated by…

General Relativity and Quantum Cosmology · Physics 2019-02-20 L. N. Granda

We present the data-driven reconstruction of gravitational theories and Dark Energy models on cosmological scales. We showcase the power of present cosmological probes at constraining these models and quantify the knowledge of their…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-22 Marco Raveri

We present a formalism to calculate the non-linear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy. Any successful modified gravity models should contain a…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-03 Kazuya Koyama , Atsushi Taruya , Takashi Hiramatsu

This research investigates the impact of modified gravity on cosmic scales, focusing on $f(Q)$ cosmology. By applying energy conditions, the study reconstructs various $f(Q)$ models, considering an accelerating Universe, quintessence, and a…

General Relativity and Quantum Cosmology · Physics 2025-04-14 Irfan Mahmood , Hira Sohail , Allah Ditta , S. H. Shekh , Anil Kumar Yadav

Considering a well-motivated $f(R)$ modified-gravity model, in which an exponential function of the curvature is included, in this paper we implement a statistical data analysis to set constraints on the parameters of the model, taking into…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-01 Mario A. Acero , A. Oliveros

Most cosmological constraints on modified gravity are obtained assuming that the cosmic evolution was standard $\Lambda$CDM in the past and that the present matter density and power spectrum normalization are the same as in a $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Laura Taddei , Luca Amendola

This study is devoted to the implications of scale-dependent gravity in Cosmology. Redshift-space distortion data indicate that there is a tension between $\Lambda$CDM and available observations as far as the value of the rms density…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Grigoris Panotopoulos , Ángel Rincón

In this paper, we use genetic algorithms, a specific machine learning technique, to achieve a model-independent reconstruction of $f(T)$ gravity. By using $H(z)$ data derived from cosmic chronometers and radial Baryon Acoustic Oscillation…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-09 Redouane El Ouardi , Amine Bouali , Imad El Bojaddaini , Ahmed Errahmani , Taoufik Ouali

We apply Gaussian processes and Hubble function data in $f(T)$ cosmology, to reconstruct for the first time the $f(T)$ form in a model-independent way. In particular, using $H(z)$ datasets coming from cosmic chronometers as well as from the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Yi-Fu Cai , Martiros Khurshudyan , Emmanuel N. Saridakis

Not much by themselves, aparently. We try to reconstruct the scale factor $a(t)$ of the universe from the SNe Ia data, i.e. the luminosity distance $d_{L}(z)$, using only the cosmological principle and the assumption that gravitation is…

General Relativity and Quantum Cosmology · Physics 2017-06-19 İbrahim Semiz , A. Kazım Çamlıbel

In this work, we present a method for numerically solving the Friedmann equations of modified $f(\mathcal{G})$ gravity in the presence of pressureless matter. This method enables us to predict the redshift behaviour of the Hubble expansion…

General Relativity and Quantum Cosmology · Physics 2024-11-08 Santosh V. Lohakare , Soumyadip Niyogi , B. Mishra

We develop the reconstruction program for the number of modified gravities: scalar-tensor theory, $f(R)$, $F(G)$ and string-inspired, scalar-Gauss-Bonnet gravity. The known (classical) universe expansion history is used for the explicit and…

High Energy Physics - Theory · Physics 2010-04-06 Shin'ichi Nojiri , Sergei D. Odintsov
‹ Prev 1 2 3 10 Next ›