# New inhomogeneous universes in scalar-tensor and f(R) gravity

## TL;DR

This paper introduces a new family of inhomogeneous, spherically symmetric solutions in scalar-tensor and f(R) gravity, expanding the understanding of cosmological models with scalar fields and their potential applications.

## Contribution

It constructs a novel 4-parameter family of solutions in Brans-Dicke gravity using a seed solution and conformal transformations, linking scalar-tensor and f(R) theories.

## Key findings

- Includes previously known solutions as special cases
- Provides solutions that are dynamical and asymptotically FLRW
- Solves field equations for f(R)=R^n gravity

## Abstract

A new family of spherically symmetric inhomogeneous solutions of Brans-Dicke gravity is generated using the Fonarev solution of general relativity as a seed and a map from the Einstein to the Jordan conformal frame. The Brans-Dicke scalar field self-interacts with a power-law or inverse power-law potential in the Jordan frame. This 4-parameter family of geometries, which is dynamical and asymptotically Friedmann-Lemaitre-Robertson-Walker, contains as special cases two previously known classes of solutions and solves also the field equations of $f(R)=R^n$ gravity