English
Related papers

Related papers: Breaking degeneracies in modified gravity with hig…

200 papers

We find general parameterizations for generic off-diagonal spacetime metrics and matter sources in general relativity (GR) and modified gravity theories when the field equations decouple with respect to certain types of nonholonomic frames…

General Relativity and Quantum Cosmology · Physics 2014-12-25 Tamara Gheorghiu , Olivia Vacaru , Sergiu I. Vacaru

General Relativity (GR) describes gravitation well at the energy scales which we have so far been able to achieve or detect. However, we do not know whether GR is behind the physics governing stronger gravitational field regimes, such as…

General Relativity and Quantum Cosmology · Physics 2012-09-13 Priscilla Canizares , Jonathan R. Gair , Carlos F. Sopuerta

Cosmological parameter estimation exercises usually make the approximation that the three standard neutrinos have degenerate mass, which is at odds with recent terrestrial measurements of the difference in the square of neutrino masses. In…

Astrophysics · Physics 2009-11-11 Anze Slosar

We study second-order cosmological perturbations in scalar-tensor models of dark energy that satisfy local gravity constraints, including f(R) gravity. We derive equations for matter fluctuations under a sub-horizon approximation and…

Astrophysics · Physics 2010-10-12 Takayuki Tatekawa , Shinji Tsujikawa

In the context of $f(R)$ theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. Using a completely general procedure, we find the exact fourth-order differential equation for the matter…

Astrophysics · Physics 2008-11-26 A. de la Cruz-Dombriz , A. Dobado , A. L. Maroto

Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity.…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-03 Nicola Bellomo , Emilio Bellini , Bin Hu , Raul Jimenez , Carlos Pena-Garay , Licia Verde

The mass-sheet degeneracy is a well-known problem in gravitational lensing which limits our capability to infer astrophysical lens properties or cosmological parameters from observations. As the number of gravitational wave observations…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 Paolo Cremonese , Jose María Ezquiaga , Vincenzo Salzano

Based on the DUSTGRAIN-pathfinder suite of simulations, we investigate observational degeneracies between nine models of modified gravity and massive neutrinos. Three types of machine learning techniques are tested for their ability to…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Julian Merten , Carlo Giocoli , Marco Baldi , Massimo Meneghetti , Austin Peel , Florian Lalande , Jean-Luc Starck , Valeria Pettorino

We compare void size and clustering statistics for nDGP and $f(R)$ gravity models and GR using N-body simulations. We show how it is critical to consider the statistics derived from mock galaxy catalogs rather than the dark matter halos…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Christopher Wilson , Rachel Bean

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Tomasz Denkiewicz , Vincenzo Salzano

We use large volume N-body simulations to predict the clustering of dark matter in redshift space in f(R) modified gravity cosmologies. This is the first time that the nonlinear matter and velocity fields have been resolved to such a high…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Elise Jennings , Carlton M. Baugh , Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

If general relativity is the correct theory of physics on large scales, then there is a differential equation that relates the Hubble expansion function, inferred from measurements of angular diameter distance and luminosity distance, to…

Astrophysics · Physics 2011-02-01 Mustapha Ishak , Amol Upadhye , David N. Spergel

In this investigation, we perform an observational statistical analysis in the theory of $ f(R, L_m) $ gravity. The proposed theoretical model is based on the Ricci scalar's non-linear contribution. We use a distinct parameterization for…

General Relativity and Quantum Cosmology · Physics 2024-08-30 J. K. Singh , Shaily , Akanksha Singh , Harshna Balhara , Joao R. L. Santos

We perform multi-plane ray-tracing using the GLAMER gravitational lensing code within high-resolution light-cones extracted from the CoDECS simulations: a suite of cosmological runs featuring a coupling between Dark Energy and Cold Dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Carlo Giocoli , R. Benton Metcalf , Marco Baldi , Massimo Meneghetti , Lauro Moscardini , Margarita Petkova

We study the cosmology of a specific class of nonlocal model of modified gravity, the so-called Deser-Woodard (DW) model, modifying the Einstein-Hilbert action by a term $\sim R f(\Box^{-1}R)$, where $f$ is a free function. Choosing $f$ so…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-18 Luca Amendola , Yves Dirian , Henrik Nersisyan , Sohyun Park

When recent observational evidence and the GR+FRW+CDM model are combined we obtain the result that the Universe is accelerating, where the acceleration is due to some not-yet-understood "dark sector". There has been a considerable number of…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-17 Jonathan A. Pearson

The $E_G$ statistic is a powerful probe for detecting deviations from GR by combining weak lensing (WL), real-space clustering and redshift space distortion (RSD) measurements thus probing both the lensing and the growth effective Newton…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-26 F. Skara , L. Perivolaropoulos

We present a new statistics based on the turn-around radii of cluster halos to break the dark sector degeneracy between the $\Lambda$CDM model and the alternative ones with $f(R)$ gravity and massive neutrinos ($\nu$) characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-07 Jounghun Lee , Marco Baldi

Owing to their more extensive sky coverage and tighter control on systematic errors, future deep weak lensing surveys should provide a better statistical picture of the dark matter clustering beyond the level of the power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Joseph Smidt , Alan Heavens , Peter Coles , Asantha Cooray

We discuss the galaxy clustering based on thermodynamics and statistical mechanics in the expanding universe in a modified theory of gravity. The modified general relativity (MGR) is developed using the regular line element field to…

General Physics · Physics 2023-02-15 Abdul W. Khanday , Sudhaker Upadhyay , Prince A. Ganai