# $\mathcal{N}$-extended Maxwell supergravities as Chern-Simons theories in three spacetime dimensions

## TL;DR

This paper introduces a new class of three-dimensional $
$-extended supergravity theories based on Maxwell superalgebras, enabling constructions without a cosmological constant and connecting to AdS-Lorentz supergravity via flat limits.

## Contribution

It develops novel $
$-extended Maxwell supergravity models with internal symmetry, expanding the landscape of supergravity theories in three dimensions.

## Key findings

- Constructed supergravity actions without cosmological constant.
- Derived theories as flat limits of AdS-Lorentz supergravity.
- Highlighted role of $ ext{so}(
)$ generators for non-degenerate invariant forms.

## Abstract

We present a new class of three-dimensional $\mathcal{N}$-extended supergravity theories based on the $\mathcal{N}$-extended Maxwell superalgebra with central charges and $\mathfrak{so}(\mathcal{N})$ internal symmetry generators. The presence of $\mathfrak{so}(\mathcal{N})$ generators is required in order to define a non-degenerate invariant inner product. Such symmetry allows us to construct an alternative supergravity action without cosmological constant term. Interestingly, the new theories can be obtained as a flat limit of a $\mathcal{N}$-extended AdS-Lorentz supergravity theories enlarged with $\mathfrak{so}(\mathcal{N})$ gauge fields.