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We perform N-body simulations for $f(T)$ gravity using the ME-Gadget code, in order to investigate for the first time the structure formation process in detail. Focusing on the power-law model, and considering the model-parameter to be…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Yiqi Huang , Jiajun Zhang , Xin Ren , Emmanuel N. Saridakis , Yi-Fu Cai

We revisit the issue of interpreting the results of large volume cosmological simulations in the context of large scale general relativistic effects. We look for simple modifications to the nonlinear evolution of the gravitational potential…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-17 Oliver Hahn , Aseem Paranjape

Simulation based inference has seen increasing interest in the past few years as a promising approach to model the non linear scales of galaxy clustering. The common approach using Gaussian process is to train an emulator over the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Tyann Dumerchat , Julian Bautista

Many theories of modified gravity, including the well studied Horndeski models, are characterized by a screening mechanism that ensures that standard gravity is recovered near astrophysical bodies. In a recently introduced class of…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Ryo Saito , Daisuke Yamauchi , Shuntaro Mizuno , Jérôme Gleyzes , David Langlois

We investigate scalar-tensor theories where matter couples to the scalar field via a kinetically dependent conformal coupling. These models can be seen as the low-energy description of invariant field theories under a global Abelian…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-29 Philippe Brax , Patrick Valageas

We present a class of modified-gravity theories which we call ultra-local models. We add a scalar field, with negligible kinetic terms, to the Einstein-Hilbert action. We also introduce a conformal coupling to matter. This gives rise to a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Philippe Brax , Luca Alberto Rizzo , Patrick Valageas

We investigate the impact of nonlinear evolution of the gravitational potentials in the LCDM model on the Integrated Sachs-Wolfe (ISW) contribution to the CMB temperature power spectrum, and on the cross-power spectrum of the CMB and a set…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Robert E. Smith , Carlos Hernandez-Monteagudo , Uros Seljak

We present the results of a large library of cosmological N-body simulations, using power-law initial spectra. The nonlinear evolution of the matter power spectra is compared with the predictions of existing analytic scaling formulae based…

We present an upgraded version of \textsc{MG-MAMPOSSt}, an extension of the \textsc{MAMPOSSt} algorithm that performs Bayesian fits of models of mass and velocity anisotropy profiles to the distribution of tracers in projected phase space,…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Lorenzo Pizzuti , Ippocratis D. Saltas , Luca Amendola

We determine the conditions for which the constraints from lunar laser ranging on the time evolution of the local gravitational constant can be extrapolated to impose constraints on the time evolution of the cosmological gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-13 Clare Burrage , Johannes Dombrowski

We consider the challenging problem of obtaining an analytic understanding of realistic astrophysical dynamics in the presence of a Vainshtein screened fifth force arising from infrared modifications of General Relativity. In particular, we…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Melinda Andrews , Yi-Zen Chu , Mark Trodden

We carry out a suite of cosmological simulations of modified action f(R) models where cosmic acceleration arises from an alteration of gravity instead of dark energy. These models introduce an extra scalar degree of freedom which enhances…

Astrophysics · Physics 2008-12-30 Hiroaki Oyaizu , Marcos Lima , Wayne Hu

We study the growth of structures in modified gravity models where the Poisson equation and the relationship between the two Newtonian potentials are modified by explicit functions of space and time. This parameterisation applies to the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 Philippe Brax , Patrick Valageas

We present high signal-to-noise measurements of the acoustic scale in the presence of nonlinear growth and redshift distortions using 320(Gpc/h)^3 of cosmological PM simulations. Using simple fitting methods, we obtain robust measurements…

Astrophysics · Physics 2009-08-21 Hee-Jong Seo , Ethan R. Siegel , Daniel J. Eisenstein , Martin White

Galaxy surveys are an important probe for superimposed oscillations on the primordial power spectrum of curvature perturbations, which are predicted in several theoretical models of inflation and its alternatives. In order to exploit the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-27 Mario Ballardini , Riccardo Murgia , Marco Baldi , Fabio Finelli , Matteo Viel

We consider a scalar field which is generallly non-minimally coupled to gravity and has a characteristic cubic Galilean-like term in the kinetic part of the action, in presence of a generic self-interaction as a candidate Dark Energy model.…

General Relativity and Quantum Cosmology · Physics 2020-01-15 Somnath Bhattacharya , Pradip Mukherjee , Amit Singha Roy , Anirban Saha

We investigate the non-linear evolution of matter perturbations in $f(R)$ models with the Chameleon screening mechanism. The novel feature of our investigation is an iterative solution for the non-linear equation for the scalar field $\chi…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-30 Sharvari Nadkarni-Ghosh , Tanush Reddy Vaka

Non-linear gravitational clustering in a universe dominated by dark energy, modelled by a `quintessence' scalar field, and cold dark matter with space-time varying mass is studied. Models of this type, where the variable mass is induced by…

Astrophysics · Physics 2009-11-07 S. Matarrese , M. Pietroni , C. Schimd

While large scale primordial non-Gaussianity is strongly constrained by present-day data, there are no such constraints at Mpc scales. Here we investigate the effect of significant small-scale primordial non-Gaussianity on structure…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Clément Stahl , Thomas Montandon , Benoit Famaey , Oliver Hahn , Rodrigo Ibata

We have investigated structure formation in the $\gamma$ gravity $f(R)$ model with {\it N}-body simulations. The $\gamma$ gravity model is a proposal which, unlike other viable $f(R)$ models, not only changes the gravitational dynamics, but…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-09 Marcelo Vargas dos Santos , Hans A. Winther , David F. Mota , Ioav Waga