Stability of cosmic structures in scalar-tensor theories of gravity

TL;DR

This paper investigates a specific scalar-tensor gravity model, deriving an exact solution, analyzing the stability of cosmic structures, and constraining model parameters using observational data from supernovae and solar system tests.

Contribution

It provides an exact analytical background solution and links observational constraints to the stability of cosmic structures in a scalar-tensor gravity model.

Findings

Model parameters are constrained by observational data.

Analytical solution for the background universe is derived.

Bounds on parameters from structure stability are established.

Abstract

In the present work we study a concrete model of Scalar--Tensor theory of gravity characterized by two free parameters, and compare its predictions against observational data and constraints coming from supernovae, solar system tests as well as the stability of cosmic structures. First an exact analytical solution at the background level is obtained. Then using that solution the expression for the turnaround radius is computed. Finally we show graphically how current data and limits put bounds on the parameters of the model at hand.