Duality-covariant particles and exotic branes

Abstract

In this paper we construct duality-covariant worldvolume dynamics of particles and branes. We extend known actions and phase space formulations to include the hidden $E_8$ symmetry of 11D supergravity, analogous to the Ehlers symmetry of 4D gravity. Making the worldvolume theory manifestly duality-covariant requires the ancillary structure of $E_8$ exceptional field theory to be taken into account. For zero-branes, we propose an enlarged worldline model with a coadjoint orbit term to encode this. More generally, we propose worldvolume theories for arbitrary exotic branes in a way that generalises the known gauged sigma model of the Kaluza-Klein monopole. These are natural in the duality-covariant Hamiltonian formulation employed here. We discuss the case of zero-branes in eleven dimensions as an illustrative example.