# Dynamically Generated Inflation from Non-Riemannian Volume Forms

## TL;DR

This paper introduces a modified gravity model using non-Riemannian volume forms that naturally generates an inflationary potential, leading to cosmological predictions consistent with current observations.

## Contribution

It presents a novel gravity model with non-Riemannian volume elements that produce inflationary dynamics without initial matter fields.

## Key findings

- Predicts spectral index n_s ≈ 0.96
- Predicts tensor-to-scalar ratio r ≈ 0.002
- Compatible with observational data for 60 e-folds

## Abstract

We propose a simple modified gravity model without any initial matter fields in terms of several alternative non-Riemannian spacetime volume elements within the metric (second order) formalism. We show how the non-Riemannian volume-elements, when passing to the physical Einstein frame, create a canonical scalar field and produce dynamically a non-trivial inflationary-type potential for the latter with a large flat region and a stable low-lying minimum. We study the evolution of the cosmological solutions from the point of view of theory of dynamical systems. The theory predicts the spectral index $n_s \approx 0.96$ and the tensor-to-scalar ratio $r \approx 0.002$ for 60 e-folds, which is in accordance with the observational data. In the future Euclid and SPHEREx missions or the BICEP3 experiment are expected to provide experimental evidence to test those predictions.