# Reconstruction of GR cosmological solutions in modified gravity theories

## TL;DR

This paper explores exact cosmological solutions in generalized scalar-tensor gravity models, demonstrating their similarity to Einstein gravity in perturbation parameters and providing specific inflationary solutions.

## Contribution

It introduces a method to find exact solutions in modified gravity theories with non-minimal couplings, extending the understanding of cosmological models beyond General Relativity.

## Key findings

- Perturbation parameters match Einstein gravity with high precision.
- Derived exact solutions for power-law and exponential inflation.
- Showed the viability of modified gravity models for cosmological inflation.

## Abstract

We study the special class of the exact solutions in cosmological models based on the Generalized Scalar-Tensor Gravity with non-minimal coupling of a scalar field to the Ricci scalar and to the Gauss-Bonnet scalar in 4D Friedmann universe corresponding to similar ones in GR. The parameters of cosmological perturbations in such models correspond to the case of Einstein gravity with a high precision. As the example of proposed approach, we obtain the exact solutions for the power-law and exponential power-law inflation.