Multisymplectic AKSZ sigma models

TL;DR

This paper extends the AKSZ sigma-model construction to multisymplectic target spaces with arbitrary degree forms, unifying various gauge theories including higher-dimensional Chern-Simons and gravity in a covariant framework.

Contribution

It introduces a higher-derivative generalization of AKSZ models with inhomogeneous forms, connecting multisymplectic geometry to gauge theories via a Chern-Weil map.

Findings

Reformulation of gauge theories as multisymplectic AKSZ models

Establishment of a higher-derivative AKSZ action invariant under gauge transformations

Connection between multisymplectic AKSZ and standard multisymplectic formulations

Abstract

The Alexandrov-Kontsevich-Schwarz-Zaboronsky (AKSZ) construction encodes all the data of a topological sigma-model in the finite-dimensional symplectic $Q$-manifold. Relaxing the nondegeneracy condition i.e. considering a presymplectic form instead, extends the construction to non-topological models. The gauge-invariant action functional of (presymplectic) AKSZ sigma model is written in terms of space-time differential forms and can be seen as a covariant multidimensional analogue of the usual 1st order Hamiltonian action. In this work, we show that the AKSZ construction has a natural generalisation where the target space $Q$-manifold is equipped with a form of arbitrary degree $\Omega$ (possibly inhomogeneous) which is $(\mathrm{d}+L_Q)$-closed. This data defines a higher-derivative generalisation of the AKSZ action which is still invariant under the natural gauge transformations determined by $Q$ and which is efficiently formulated in terms of a version of Chern-Weil map introduced by Kotov and Strobl. It turns out that a variety of interesting gauge theories, including higher-dimensional Chern-Simons theory, MacDowell-Mansouri-Stelle-West action and self-dual gravity as well as its higher spin extension, can be concisely reformulated as such multisymplectic AKSZ models. We also present a version of the construction in the setup of PDE geometry and demonstrate that the counterpart of the multisymplectic AKSZ action is precisely the standard multisymplectic formulation, where the Chern-Weil map corresponds to the usual pullback map.