English
Related papers

Related papers: $k$-evolution: a relativistic N-body code for clus…

200 papers

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the…

Astrophysics · Physics 2009-10-31 Hiromitsu Magira , Y. P. Jing , Yasushi Suto

We present a new approach to describe statistics of the non-linear matter density field that exploits a degeneracy in the impact of different cosmological parameters on the linear dimensionless matter power spectrum, $\Delta^2_{\rm L}(k)$.…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-29 Ariel G. Sanchez , Andrés N. Ruiz , Jenny Gonzalez Jara , Nelson D. Padilla

We present the first cosmological simulations that consistently include nonlinear clustering dark energy evolved as a fluid with the numerical hydrodynamics code Nefertiti. Dark energy perturbations become fully nonlinear on small scales,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Linda Blot , Théo Gayoux , Fabian Schmidt , Pier Stefano Corasaniti , Bastien de Ligondes

We present asevolution, a cosmological N-body code developed based on gevolution, which consistently solves for the (a)symmetron scalar field and metric potentials within the weak-field approximation. In asevolution, the scalar field is…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-04 Øyvind Christiansen , Farbod Hassani , Mona Jalilvand , David F. Mota

The abundance and distribution of collapsed objects such as galaxy clusters will become an important tool to investigate the nature of dark energy and dark matter. Number counts of very massive objects are sensitive not only to the equation…

Astrophysics · Physics 2010-05-12 L. R. Abramo , R. C. Batista , L. Liberato , R. Rosenfeld

The potential is a constant to linear order in cosmological gravitational clustering. In this Letter we present results of testing the conjecture, proposed by Pauls and Melott (1995), that the effect of nonlinear evolution on the potential…

Astrophysics · Physics 2009-10-28 Adrian L. Melott , B. S. Sathyaprakash , Varun Sahni

We study structure formation using relativistic cosmological linear perturbation theory in the presence of intrinsic and relative (with respect to matter) non-adiabatic dark energy perturbations. For different dark energy models we assess…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Hermano Velten , Raquel Fazolo

This paper explores the generalized ghost dark energy model in the framework of $f(\textsl{Q}, \textsl{L}_{m})$ gravity, where $\textsl{Q}$ represents the non-metricity scalar and $\textsl{L}_{m}$ denotes the matter-Lagrangian density. We…

General Relativity and Quantum Cosmology · Physics 2025-01-03 M. Zeeshan Gul , M. Sharif , Shan Ali Qureshi , Baiju Dayanandan

The evidence in favor of a dark energy component dominating the Universe, and driving its presently accelerated expansion, has progressively grown during the last decade of cosmological observations. If this dark energy is given by a…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 Marco Baldi

Adaptive SPH and N-body simulations were carried out to study the evolution of the equilibrium structure of dark matter halos that result from the gravitational instability and fragmentation of cosmological pancakes. Such halos resemble…

Astrophysics · Physics 2009-11-06 Marcelo Alvarez , Paul R. Shapiro , Hugo Martel

Special high-accuracy direct force summation N-body algorithms and their relevance for the simulation of the dynamical evolution of star clusters and other gravitating N-body systems in astrophysics are presented, explained and compared…

Astrophysics · Physics 2007-05-23 R. Spurzem

We analyse the evolution of cosmological perturbations which leads to the formation of large isolated voids in the Universe. We assume that initial perturbations are spherical and all components of the Universe (radiation, matter and dark…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Bohdan Novosyadlyj , Maksym Tsizh , Yurij Kulinich

Current cosmological data indicate that our universe contains a substantial component of dark vacuum energy that is driving the cosmos to accelerate. We examine the immediate and longer term consequences of this dark energy (assumed here to…

Astrophysics · Physics 2010-12-09 Michael T. Busha , Fred C. Adams , Risa H. Wechsler , August E. Evrard

We present a framework for general relativistic N-body simulations in the regime of weak gravitational fields. In this approach, Einstein's equations are expanded in terms of metric perturbations about a Friedmann-Lema\^itre background,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Julian Adamek , Ruth Durrer , Martin Kunz

We present the new relativistic cosmological particle-mesh code $\texttt{fRevolution}$, based on $\texttt{gevolution}$, aimed at simulating non-linear structure formation in $f(R)$ gravity. We introduce the general framework and…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-31 Lorenzo Reverberi , David Daverio

Modified gravity theories constitute viable alternatives to the standard cosmological model for explaining the observed late-time accelerated expansion of the Universe. The Effective Field Theory of Dark Energy (EFTofDE) is an efficient…

This is the first in a series of papers devoted to fully general-relativistic $N$-body simulations applied to late-time cosmology. The purpose of this paper is to present the combination of a numerical relativity scheme, discretization…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-29 David Daverio , Yves Dirian , Ermis Mitsou

We consider the prospects for dark matter/energy unification in k-essence type theories. General mappings are established between the k-essence scalar field, the hydrodynamic and braneworld descriptions. We develop an extension of the…

General Relativity and Quantum Cosmology · Physics 2009-08-11 Neven Bilic , Gary B. Tupper , Raoul D. Viollier

Using a formalism recently introduced we study the decaying of the cosmological parameter during the early evolution of an universe, whose evolution is governed by a vacuum equation of state. We use a stochastic approach in a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Mauricio Bellini

We introduce the N-body simulation technique to follow structure formation in linear and nonlinear regimes for the extended quintessence models (scalar-tensor theories in which the scalar field has a self-interaction potential and behaves…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-04 Baojiu Li , David F. Mota , John D. Barrow