English
Related papers

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

200 papers

We study new FRW type cosmological models of modified gravity treated on the background of Palatini approach. These models are generalization of Einstein gravity by the presence of a scalar field non-minimally coupled to the curvature. The…

General Relativity and Quantum Cosmology · Physics 2012-03-13 A. Borowiec , M. Kamionka , A. Kurek , M. Szydlowski

In this work, we extend the bottom-up reconstruction framework of $F(R)$ gravity to other modified gravities, and in particular for $f(\phi)R$ and mimetic $F(R)$ gravities. We investigate which are the important conditions in order for the…

General Relativity and Quantum Cosmology · Physics 2018-03-14 S. D. Odintsov , V. K. Oikonomou

In this research paper, we explore a well-motivated parametrization of the time-dependent deceleration parameter, characterized by a cubic form, within the context of late time cosmic acceleration. The current analysis is based on the…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Madhur Khurana , Himanshu Chaudhary , Saadia Mumtaz , S. K. J. Pacif , G. Mustafa

In the present paper, we investigate the dark energy equation of state using the Gaussian processes analysis method, without confining a particular parametrization. The reconstruction is carried out by adopting the background data including…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-11 Ming-Jian Zhang , Hong Li

This work investigates a potential time dependence of the absolute magnitude of Type Ia Supernovae (SN Ia). Employing the Gaussian Process approach, we obtain the SN Ia absolute magnitude and its derivative as a function of redshift. The…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-15 Rodrigo von Marttens , Javier Gonzalez , Jailson Alcaniz

There has been a significant interest in modifications of the standard $\Lambda$ Cold Dark Matter ($\Lambda$CDM) cosmological model prompted by tensions between certain datasets, most notably the Hubble tension. The late-time modifications…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-06 Levon Pogosian , Marco Raveri , Kazuya Koyama , Matteo Martinelli , Alessandra Silvestri , Gong-Bo Zhao , Jian Li , Simone Peirone , Alex Zucca

This paper examines the late-time accelerating Universe and the formation of large-scale structures within the modified symmetric teleparallel gravity framework, specifically using the $f(Q)$-gravity model, in light of recent cosmological…

General Relativity and Quantum Cosmology · Physics 2024-12-31 Shambel Sahlu , Amare Abebe

In the present work we describe a model-independent method of developing a plot of scale factor versus lookback time from the usual Hubble diagram of modulus data against redshift. This is the first plot of this type. We follow the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Harry I. Ringermacher , Lawrence R. Mead

There has been recent interest in the cosmological consequences of energy-momentum-powered gravity models, in which the matter side of Einstein's equations is modified by the addition of a term proportional to some power, $n$, of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 M. C. F. Faria , C. J. A. P. Martins , F. Chiti , B. S. A. Silva

We attempt to construct a Friedmann-Lemaitre-Robertson-Walker(FLRW) cosmological model in $f(R, T)$ gravity which exhibits a phase transition from deceleration to acceleration at present. We take $f(R,T) = R + 2 \lambda T$, $\lambda$ being…

General Relativity and Quantum Cosmology · Physics 2023-06-05 Anirudh Pradhan , Gopikant Goswami , Rita Rani , Aroonkumar Beesham

Reliable analytical modeling of the non-linear power spectrum (PS) of matter perturbations is among the chief pre-requisites for cosmological analyses from the largest sky surveys. This is especially true for the models that extend the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Suhani Gupta , Wojciech A. Hellwing , Maciej Bilicki

This paper studies linear reconstruction of partially observed functional data which are recorded on a discrete grid. We propose a novel estimation approach based on approximate factor models with increasing rank taking into account…

Statistics Theory · Mathematics 2024-05-22 Maximilian Ofner , Siegfried Hörmann

In this paper, an attempt is made to construct a Friedmann-Lemaitre-Robertson-Walker model in $f(R,T)$ gravity with a perfect fluid that yields acceleration at late times. We take $f(R,T)$ as $R$ + $8\pi \mu T$. As in the $\Lambda$CDM…

General Relativity and Quantum Cosmology · Physics 2023-04-25 Anirudh Pradhan , Gopikant Goswami , Aroonkumar Beesham

We study the possibility of realizing a growth rate of matter density perturbations lower than that in General Relativity. Using the approach of the effective field theory of modified gravity encompassing theories beyond Horndeski, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Shinji Tsujikawa

Modifications on the predictions about the matter power spectrum based on the hypothesis of a tiny contribution from a degenerate Fermi gas (DFG) test-fluid to some dominant cosmological scenario are investigated. Reporting about the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 E. L. D. Perico , Alex E. Bernardini

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

The modified gravity is considered in the framework of the holographic dark energy. An analysis of the autonomous system, the critical points and their stability is presented. Unlike the dark energy models based on $f(R)$, it is found that…

General Relativity and Quantum Cosmology · Physics 2020-03-18 L. N. Granda , G. D. Rojas

We study the dynamics of a modified-gravity theory, which is supplemented by an extended Gibbons-Hawking-York boundary term and incorporates diffeomorphism violation through nondynamical background fields denoted as $u$ and $s^{\mu\nu}$ in…

High Energy Physics - Theory · Physics 2022-09-07 Carlos M. Reyes , Marco Schreck

The statistics of dark matter halos is an essential component of understanding the nonlinear evolution in modified gravity cosmology. Based on a series of modified gravity N-body simulations, we investigate the halo mass function,…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-21 Youcai Zhang , Pengjie Zhang , Xiaohu Yang , Weiguang Cui

We propose a class of actions for the spacetime metric that introduce corrections to the Einstein-Hilbert Lagrangian depending on the logarithm of some curvature scalars. We show that for some choices of these invariants the models are…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Ignacio Navarro , Karel Van Acoleyen
‹ Prev 1 4 5 6 7 8 10 Next ›