# Disformal Transformations in Scalar-Torsion Gravity

## TL;DR

This paper explores disformal transformations in scalar-torsion gravity, identifying invariant action classes and proposing their use as teleparallel analogues of beyond Horndeski theories.

## Contribution

It introduces a class of scalar-torsion actions invariant under disformal transformations, expanding the framework of teleparallel gravity models.

## Key findings

- Identified a generic class of invariant scalar-torsion actions.
- Derived explicit terms for the simplest subclass.
- Proposed these actions as teleparallel analogues of beyond Horndeski theories.

## Abstract

We study disformal transformations in the context of scalar extensions to teleparallel gravity, in which the gravitational interaction is mediated by the torsion of a flat, metric compatible connection. We find a generic class of scalar-torsion actions which is invariant under disformal transformations, and which possesses different invariant subclasses. For the most simple of these subclasses we explicitly derive all terms that may appear in the action. We propose to study actions from this class as possible teleparallel analogues of healthy beyond Horndeski theories.