Cosmological simulations: the role of scalar fields

TL;DR

This paper uses numerical N-body simulations to compare standard and alternative dark matter models, focusing on scalar-tensor theories with scalar fields affecting gravitational forces, to understand their impact on large-scale structure formation.

Contribution

It introduces a detailed comparison of ΛCDM with scalar-tensor theories incorporating scalar fields, highlighting their effects on cosmic structure formation through simulations.

Findings

Scalar fields modify gravitational interactions via Yukawa potentials.

Differences observed in large-scale structure at z=0 across models.

Scalar-tensor models show distinct features compared to ΛCDM.

Abstract

We present numerical $N$-body simulation studies of large-scale structure formation. The main purpose of these studies is to analyze the several models of dark matter and the role they played in the process of large-scale structure formation. We analyze the standard and more successful case, i.e., the cold dark matter with cosmological constant ($\Lambda$CDM). We compare the results of this model with the corresponding results of other alternative models, in particular, the models that can be built from the Newtonian limit of alternative theories of gravity like scalar-tensor theories. An specific model is the one that considers that the scalar field is non-minimally coupled to the Ricci scalar in the Einstein-Hilbert Lagrangian that gives, in the Newtonian limit an effective gravitational force that is given by two contributions: the standard Newtonian potential plus a Yukawa potential that comes from a massive scalar field. Comparisons of the models are done by analyzing the snapshots of the $N$-body system at z=0 for several values of the SF parameters.