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Related papers: Emulation of $f(R)$ modified gravity from $\Lambda…

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We investigate the impact on cosmological observables of $f(Q)$-gravity, a specific class of modified gravity models in which gravity is described by the non-metricity scalar, $Q$. In particular we focus on a specific model which is…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Noemi Frusciante

We consider the evolution of cosmological gravitational waves in scalar-tensor theory and $F(R)$ gravity theory as typical models of the modified gravity. Although the propagation speed is not changed from the speed of light, the…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Shin'ichi Nojiri , Sergei D. Odintsov

We consider modified gravity models driven by a scalar field whose effects are screened in high density regions due to the presence of non-linearities in its interaction potential and/or its coupling to matter. Our approach covers…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Philippe Brax , Anne-Christine Davis , Baojiu Li , Hans A. Winther

In order to deal with a large cosmological constant a relaxation mechanism based on modified gravity has been proposed recently. By virtue of this mechanism the effect of the vacuum energy density of a given quantum field/string theory (no…

General Relativity and Quantum Cosmology · Physics 2012-01-31 Spyros Basilakos , Florian Bauer , Joan Sola

Given the remarkable success of the $\Lambda$CDM model in fitting various cosmological observations, a pertinent question in assessing the phenomenological viability of modified gravity theories is whether they can reproduce an exactly…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Saikat Chakraborty , Jibitesh Dutta , Daniele Gregoris , Khamphee Karwan , Wompherdeiki Khyllep

Ground and space-based sky surveys enable powerful cosmological probes based on measurements of galaxy properties and the distribution of galaxies in the Universe. These probes include weak lensing, baryon acoustic oscillations, abundance…

In this work, we analyze the Einstein-scalar-Gauss-Bonnet (EsGB) theory of gravity in a cosmological context using the formalism of dynamical systems. We obtain the equations of motion of the theory and introduce an appropriate set of…

General Relativity and Quantum Cosmology · Physics 2025-09-23 Miguel A. S. Pinto , João Luís Rosa

Scientific analyses often rely on slow, but accurate forward models for observable data conditioned on known model parameters. While various emulation schemes exist to approximate these slow calculations, these approaches are only safe if…

Instrumentation and Methods for Astrophysics · Physics 2020-04-28 Grigor Aslanyan , Richard Easther , Nathan Musoke , Layne C. Price

We focus on weak inhomogeneous models of the Universe at low redshifts, described by the Lema\^itre-Tolman-Bondi (LTB) metric. The principal aim of this work is to compare the evolution of inhomogeneous perturbations in the $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Tiziano Schiavone , Giovanni Montani

Machine learning can accelerate cosmological inferences that involve many sequential evaluations of computationally expensive data vectors. Previous works in this series have examined how machine learning architectures impact emulator…

In this paper we study cosmological perturbations with $f(R)$ gravity scalaron. We consider epoch of transition from early general relativity (GR) phase to late time non-GR phase of cosmogenic history for a viable $f(R)$ gravity Lagrangian…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-21 Abhijit Talukdar , Sanjeev Kalita , Shadab Alam

In this series of papers we present an emulator-based halo model for the non-linear clustering of galaxies in modified gravity cosmologies. In the first paper, we present emulators for the following halo properties: the halo mass function,…

Cosmological analyses can be accelerated by approximating slow calculations using a training set, which is either precomputed or generated dynamically. However, this approach is only safe if the approximations are well understood and…

Instrumentation and Methods for Astrophysics · Physics 2015-09-03 Grigor Aslanyan , Richard Easther , Layne C. Price

In this manuscript, we present a number of fascinating explicit reconstructions for the $f(Q)$ gravity from the background of Friedmann-La\^imatre-Robertson-Walker (FLRW) evolution history. We find the more general functions of…

General Relativity and Quantum Cosmology · Physics 2022-10-25 Gaurav N. Gadbail , Sanjay Mandal , P. K. Sahoo

Machine learning enables powerful cosmological inference but typically requires many high-fidelity simulations covering many cosmological models. Transfer learning offers a way to reduce the simulation cost by reusing knowledge across…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-23 Veena Krishnaraj , Adrian E. Bayer , Christian Kragh Jespersen , Peter Melchior

General relativity (GR) has been well tested up to solar system scales, but it is much less certain that standard gravity remains an accurate description on the largest, that is, cosmological, scales. Many extensions to GR have been studied…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Austin Peel , Valeria Pettorino , Carlo Giocoli , Jean-Luc Starck , Marco Baldi

It is well-known that allowing for spatial curvature affects constraints on cosmological parameters such as the dark energy equation of state parameters. Here we study the effect of curvature on constraints on parameters used to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jason Dossett , Mustapha Ishak

We study Modified Gravity (MG) theories by modelling the redshifted matter power spectrum in a spherical Fourier-Bessel (sFB) basis. We use a fully non-linear description of the real-space matter power-spectrum and include the lowest-order…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Dipak Munshi , Geraint Pratten , Patrick Valageas , Peter Coles , Philippe Brax

Molecular Dynamics (MD) simulation is a powerful tool for understanding the dynamics and structure of matter. Since the resolution of MD is atomic-scale, achieving long time-scale simulations with femtosecond integration is very expensive.…

Machine Learning · Computer Science 2022-04-27 Zijie Li , Kazem Meidani , Prakarsh Yadav , Amir Barati Farimani

Models of modified gravity offer promising alternatives to the concordance $\Lambda$CDM cosmology to explain the late-time acceleration of the universe. A popular such model is $f(R)$ gravity, in which the Ricci scalar in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-14 Christine Corbett Moran , Romain Teyssier , Baojiu Li