# Reconstruction of $f(R)$ gravity models for an accelerated universe using Raychaudhuri equation

## TL;DR

This paper introduces a new method using Raychaudhuri equation to reconstruct $f(R)$ gravity models for accelerated universes, but finds the models are not viable in the tested scenarios.

## Contribution

It presents an analytical reconstruction approach for $f(R)$ gravity models based on kinematic universe parameters using Raychaudhuri equation.

## Key findings

- Reconstructed $f(R)$ models for accelerating universe scenarios.
- Models involve power-law and hypergeometric functions.
- Reconstructed models are found to be non-viable.

## Abstract

A new strategy for the reconstruction of $f(R)$ gravity models have been attempted using Raychaudhuri equation. Two examples, one for an eternally accelerating universe and the other for one that mimics a ${\Lambda}$CDM expansion history have been worked out. For both the cases, the relevant $f=f(R)$ could be found out analytically. In the first case, $f(R)$ is found to be a combination of power-law terms and in the expression for the second case involves hypergeometric functions. The evolution history of the universe, given as specific values of the kinematical quantities like the jerk or the deceleration parameter, serve as the input. It is found that the corresponding $f(R)$ gravity models, in both the examples, are not viable options.