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

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Non-linear evolution of cosmological energy density fluctuations triggers deviations from Gaussianity in the temperature distribution of the cosmic microwave background. A method to estimate these deviations is proposed. N-body simulations…

Astrophysics · Physics 2009-11-07 A. M. Aliaga , V. Quilis , J. V. Arnau , D. Saez

We study the effect of two Modified Gravity (MG) theories, $f(R)$ and nDGP, on three probes of large-scale structure, the real space power spectrum estimator $Q_0$, bispectrum and voids, and validate fast approximate COLA simulations…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-28 Bartolomeo Fiorini , Kazuya Koyama , Albert Izard

Absent any indirect tests on the thermal history of the Universe prior to the formation of light nuclear elements, it is legitimate to investigate situations where, before nucleosyntheis, the sound speed of the plasma was larger than…

Astrophysics · Physics 2010-04-29 Massimo Giovannini

We investigate the evolution of the linear cosmological perturbations in f(R) gravity, an alternative to dark energy for explaining the late-time cosmic acceleration. We numerically calculate the early-time evolution with an approximation…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-16 Je-An Gu , Tse-Chun Wang , Yen-Ting Wu , Pisin Chen , W-Y. Pauchy Hwang

Interpreting observations of the Lyman-$\alpha$ forest flux power spectrum requires interpolation between a small number of expensive simulations. We present a Gaussian process emulator modelling the 1D flux power spectrum as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-17 Christian Pedersen , Andreu Font-Ribera , Keir K. Rogers , Patrick McDonald , Hiranya V. Peiris , Andrew Pontzen , Anže Slosar

In this paper we place observational constraints on the well-known $\gamma$-gravity $f(R)$ model using the latest cosmological data, namely we use the latest growth rate, Cosmic Microwave Background, Baryon Acoustic Oscillations, Supernovae…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-17 Clara Álvarez Luna , Spyros Basilakos , Savvas Nesseris

In the context of the so-called Gauss-Bonnet gravity, where the gravitational action includes function of the Gauss-Bonnet invariant, we study cosmological solutions, especially the well-known $\Lambda$CDM model. It is shown that the dark…

General Relativity and Quantum Cosmology · Physics 2011-05-09 Ratbay Myrzakulov , Diego Sáez-Gómez , Anca Tureanu

In General Relativity approximations based on the spherical collapse model such as Press--Schechter theory and its extensions are able to predict the number of objects of a certain mass in a given volume. In this paper we use a machine…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-08 Jonathan C. Betts , Carsten van de Bruck , Christian Arnold , Baojiu Li

A central problem in biomechanical studies of personalised human left ventricular (LV) modelling is estimating the material properties and biophysical parameters from in-vivo clinical measurements in a time frame suitable for use within a…

Applications · Statistics 2019-05-16 Vinny Davies , Umberto Noè , Alan Lazarus , Hao Gao , Benn Macdonald , Colin Berry , Xiaoyu Luo , Dirk Husmeier

Recent studies by Sol\`a Peracaula, G\'omez-Valent, de Cruz P\'erez and Moreno-Pulido (2019,2020) have pointed out the intriguing possibility that Brans-Dicke cosmology with constant vacuum energy density (BD-$\Lambda$CDM) may be able to…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-04 Adrià Gómez-Valent , Prajwal Hassan Puttasiddappa

We propose the mimetic $F(R)$ theory and investigate the early-time and late-time acceleration in such theory. It is demonstrated that inflation consistent with observable data may be realized in such theory. The reconstruction of realistic…

High Energy Physics - Theory · Physics 2014-12-19 Shin'ichi Nojiri , Sergei D. Odintsov

A key task in cosmology is to test the validity of general relativity (GR) at cosmological scales and, therefore, to distinguish between dark energy and modified gravity (MG) as the driver of the late-time cosmic acceleration. The decay…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-07 Xinyi Zhao , Pengjie Zhang , Fuyu Dong

In this work, we have considered a minimally modified gravity theory that effectively reproduces VCDM-like behavior to investigate its cosmological implications. The model parameters are constrained using a combination of CC, RSD, DESI BAO…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-31 Sai Swagat Mishra , Soumya Kanta Bhoi , P. K. Sahoo

We investigate the cosmological predictions of several $f(T)$ models, with up to two parameters, at both the background and the perturbation levels. Using current cosmological observations (geometric supernovae type Ia, cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-17 S. Nesseris , S. Basilakos , E. N. Saridakis , L. Perivolaropoulos

Stage IV large scale structure surveys are promising probes of gravity on cosmological scales. Due to the vast model-space in the modified gravity literature, model-independent parameterisations represent useful and scalable ways to test…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-03 Sankarshana Srinivasan , Daniel B Thomas , Peter L. Taylor

In this work, we investigate the cosmological consequences of an effective $f(Q)$ model emerging from the more general $f(Q,T)$ gravity theory under the special equation-of-state condition $\rho + p = 0$. Under this limit, the field…

General Relativity and Quantum Cosmology · Physics 2025-12-12 Anil Kumar Yadav , S. H. Shekh , N. Myrzakulov

We apply a halo velocity bias model, $\gamma_{f}$, within the Aemulus simulation suite for General Relativity (GR) to investigate its efficacy in identifying the signature of assembly bias and Modified Gravity (MG). In the investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Yirong Wang , Zhongxu Zhai , Xiaohu Yang , Jeremy L. Tinker

$f(R)$ theories of modified gravity may be compatible with current observations if the deviations from general relativity are sufficiently well screened in dense environments. In recent work [arXiv:2310.19955] we have shown that…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Bradley March , Clare Burrage , Aneesh P. Naik

Fitting a theoretical model to experimental data in a Bayesian manner using Markov chain Monte Carlo typically requires one to evaluate the model thousands (or millions) of times. When the model is a slow-to-compute physics simulation,…

Machine Learning · Statistics 2022-08-25 Steven Stetzler , Michael Grosskopf , Earl Lawrence

In this work, we consider three different $f(Q)$ models, such as power-law, exponential, and logarithmic, to study which model better mimics $\Lambda$CDM evolution theoretically. Henceforth, we determine solutions to the $f(Q)$ gravity…

General Relativity and Quantum Cosmology · Physics 2024-05-10 Gaurav N. Gadbail , P. K. Sahoo