Leibniz-Chern-Simons Theory and Phases of Exceptional Field Theory

TL;DR

This paper explores a generalized Chern-Simons theory based on Leibniz algebras, linking it to exceptional field theory and revealing new topological phases related to ${ m E}_{8(8)}$ symmetries.

Contribution

It introduces a Leibniz algebra framework for exceptional field theory, connecting gauged supergravity, generalized diffeomorphisms, and topological phases in a unified manner.

Findings

Leibniz algebra of generalized diffeomorphisms derived from a Lie algebra of enhanced symmetry.

Topological phase of ${ m E}_{8(8)}$ theory interpreted as a Chern-Simons theory for a combined algebra.

Unified algebraic structure linking Poincaré and Leibniz algebras in exceptional field theory.

Abstract

We discuss a generalization of Chern-Simons theory in three dimensions based on Leibniz (or Loday) algebras, which are generalizations of Lie algebras. Special cases of such theories appear in gauged supergravity, where the Leibniz algebra is defined in terms of the global (Lie) symmetry algebra of the ungauged limit and an embedding tensor. We show that the Leibniz algebra of generalized diffeomorphisms in exceptional field theory can similarly be obtained from a Lie algebra that describes the enhanced symmetry of an `ungauged phase' of the theory. Moreover, we show that a `topological phase' of ${\rm E}_{8(8)}$ exceptional field theory can be interpreted as a Chern-Simons theory for an algebra unifying the three-dimensional Poincar\'e algebra and the Leibniz algebra of ${\rm E}_{8(8)}$ generalized diffeomorphisms.