Linear Cosmological perturbations in $f(Q)$ Gravity

TL;DR

This paper investigates the effects of $f(Q)$ gravity on the universe's accelerated expansion and structure formation, analyzing linear perturbations and growth of matter contrasts using covariant formalism and specific models.

Contribution

It introduces a detailed analysis of linear cosmological perturbations in $f(Q)$ gravity, including the growth of matter density contrasts with new analytical techniques.

Findings

Accelerated expansion explained by $f(Q) = Q + eta Q^n$ model.

Growth of matter density contrasts analyzed in dust and radiation eras.

Quasi-static approximation applied to structure formation in $f(Q)$ gravity.

Abstract

In this manuscript, we studied the accelerated expansion history of the universe and the formations of large-scale structures using $f(Q)$ gravity model. The expansion rate of the universe within distance modulus and redshift has been performed in $f(Q)$ gravity. This work is also devoted to investigating the linear cosmological perturbations in the $f(Q)$ gravity model using the $1 + 3$ covariant formalism. The scalar and harmonic decomposition techniques are applied to find the evolution equation. The growth of matter density contrasts is analyzed with redshift $z$. Using the nonmetricity modified gravity model which is $f (Q) = Q+\alpha Q^n$, the accelerating expanding universe and the formations of the large-scale structures have been explained. The quasi-static approximation technique is applied to analyze the growth of matter contrasts. The growth of density contrast is studied within the dust and radiation-dominated universe in the presence of nonmetricity gravity.