Gravitational Coset Models

TL;DR

This paper explores gravitational coset models derived from Kac-Moody algebras, constructing bound states of dual gravitons that interpolate between exotic solutions, highlighting their algebraic structure and limitations within Einstein-Hilbert gravity.

Contribution

It introduces a novel approach to modeling gravitational bound states using coset algebras and analyzes their properties and obstructions within supergravity frameworks.

Findings

Constructed five-dimensional gravitational objects from coset models.

Identified actions for interpolating bound states of dual gravitons.

Highlighted the obstruction to these states being solutions of Einstein-Hilbert gravity.

Abstract

The algebra A(D-3)+++ dimensionally reduces to the E(D-1) symmetry algebra of (12-D)-dimensional supergravity. An infinite set of five-dimensional gravitational objects trivially embedded in D-dimensions is constructed by identifying the null geodesic motion on cosets embedded in the generalised Kac-Moody algebra A(D-3)+++. By analogy with supergravity these are bound states of dual gravitons. The metric interpolates continuously between exotic gravitational solutions generated by the action of the Geroch group but is not a continuously transforming solution of the Einstein-Hilbert action. We investigate mixed-symmetry fields in the brane sigma model, identify actions for the full interpolating bound state and understand the obstruction to the bound state being a solution of the Einstein-Hilbert action.