# Initial conditions for cosmological N-body simulations of the scalar sector of theories of Newtonian, Relativistic and Modified Gravity

@article{Valkenburg2015InitialCF, title={Initial conditions for cosmological N-body simulations of the scalar sector of theories of Newtonian, Relativistic and Modified Gravity}, author={W. Valkenburg and B. Hu}, journal={arXiv: Cosmology and Nongalactic Astrophysics}, year={2015} }

We present a description for setting initial particle displacements and field values for simulations of arbitrary metric theories of gravity, for perfect and imperfect fluids with arbitrary characteristics. We extend the Zel'dovich Approximation to nontrivial theories of gravity, and show how scale dependence implies curved particle paths, even in the entirely linear regime of perturbations. For a viable choice of Effective Field Theory of Modified Gravity, initial conditions set at high… Expand

#### 11 Citations

Initial Conditions for Accurate N-Body Simulations of Massive Neutrino Cosmologies

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The set-up of the initial conditions in cosmological N-body simulations is usually implemented by rescaling the desired low-redshift linear power spectrum to the required starting redshift… Expand

Relativistic initial conditions for N-body simulations

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Initial conditions for (Newtonian) cosmological N-body simulations are usually set by re-scaling the present-day power spectrum obtained from linear (relativistic) Boltzmann codes to the desired… Expand

Relativistic Interpretation of Newtonian Simulations for Cosmic Structure Formation

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- 2016

The standard numerical tools for studying non-linear collapse of matter are Newtonian $N$-body simulations. Previous work has shown that these simulations are in accordance with General Relativity… Expand

A parametrisation of modified gravity on nonlinear cosmological scales

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- 2016

Viable modifications of gravity on cosmological scales predominantly rely on screening mechanisms to recover Einstein's Theory of General Relativity in the Solar System, where it has been well… Expand

Scalar-Fluid theories: cosmological perturbations and large-scale structure

- Physics
- 2015

Recently a new Lagrangian framework was introduced to describe interactions between scalar fields and relativistic perfect fluids. This allows two consistent generalizations of coupled quintessence… Expand

GRAMSES: a new route to general relativistic N-body simulations in cosmology. Part II. Initial conditions

- Physics
- 2020

We address the generation of initial conditions (ICs) for GRAMSES, a code for nonlinear general relativistic (GR) $N$-body cosmological simulations recently introduced in Ref. [1]. GRAMSES adopts a… Expand

GRAMSES: a new route to general relativistic N-body simulations in cosmology. Part I. Methodology and code description

- Physics
- 2019

We present GRAMSES, a new pipeline for nonlinear cosmological $N$-body simulations in General Relativity (GR). This code adopts the Arnowitt-Deser-Misner (ADM) formalism of GR, with constant mean… Expand

gevolution: a cosmological N-body code based on General Relativity

- Physics
- 2016

We present a new N-body code, gevolution, for the evolution of large scale structure in the Universe. Our code is based on a weak field expansion of General Relativity and calculates all six metric… Expand

hi_class background evolution, initial conditions and approximation schemes

- Physics
- 2019

Cosmological datasets have great potential to elucidate the nature of dark energy and test gravity on the largest scales available to observation. Theoretical predictions can be computed with… Expand

Effective field theory of dark energy: A review

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- 2019

The discovery of cosmic acceleration has triggered a consistent body of theoretical work aimed at modeling its phenomenology and understanding its fundamental physical nature. In recent years, a… Expand

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