Non-linear structure formation in the "Running FLRW" cosmological model

TL;DR

This paper introduces cosmological N-body simulations for the R-FLRW model, which extends b4CDM with a time-varying vacuum energy and gravitational constant, enabling analysis of structure formation in this alternative cosmology.

Contribution

First full non-linear growth simulations of the R-FLRW cosmology, incorporating analytical adaptations and consistent with CMB data, allowing detailed property analysis of halos and sub-halos.

Findings

Deviations of R-FLRW from b4CDM quantified

Simulations enable analysis of halo and sub-halo properties

Framework to test R-FLRW with future observations

Abstract

We present a suite of cosmological N-body simulations describing the "Running Friedmann-Lema{\"i}tre-Robertson-Walker" (R-FLRW) cosmological model. This model is based on quantum field theory in a curved space-time and extends {\Lambda}CDM with a time-evolving vacuum density, {\Lambda}(z), and time-evolving gravitational Newton's coupling, G(z). In this paper we review the model and introduce the necessary analytical treatment needed to adapt a reference N-body code. Our resulting simulations represent the first realisation of the full growth history of structure in the R-FLRW cosmology into the non-linear regime, and our normalisation choice makes them fully consistent with the latest cosmic microwave background data. The post-processing data products also allow, for the first time, an analysis of the properties of the halo and sub-halo populations. We explore the degeneracies of many statistical observables and discuss the steps needed to break them. Furthermore, we provide a quantitative description of the deviations of R-FLRW from {\Lambda}CDM, which could be readily exploited by future cosmological observations to test and further constrain the model.