# Non-singular and ghost-free infinite derivative gravity with torsion

## TL;DR

This paper develops a comprehensive infinite derivative gravity theory with torsion, demonstrating ghost and singularity freedom around Minkowski space when torsion is an axial background field, using the Palatini approach.

## Contribution

It introduces the most general quadratic curvature action with torsion and infinite derivatives, analyzing its ghost-free and singularity-free properties in a novel way.

## Key findings

- Decoupling of metric and torsion in the axial background case
- Ghost and singularity freedom achieved for fermionic sources
- Application of the Palatini approach to infinite derivative gravity

## Abstract

We present the most general quadratic curvature action with torsion including infinite covariant derivatives and study its implications around the Minkowski background via the Palatini approach. Provided the torsion is solely given by the background axial field, the metric and torsion are shown to decouple, and both of them can be made ghost and singularity free for a fermionic source.