Product CFTs, gravitational cloning, massive gravitons and the space of gravitational duals

TL;DR

This paper explores how multi-graviton theories emerge from products of large-N CFTs within the AdS/CFT framework, highlighting limitations on massless gravitons and the possibility of multiple massive gravitons via specific couplings.

Contribution

It demonstrates that multi-graviton theories can be constructed from product CFTs with coupled boundary conditions, revealing the structure of their gravitational duals and limitations on massless gravitons.

Findings

Only one massless graviton can be interacting.

Multiple interacting massive gravitons are possible.

Gravitational duals correspond to product manifolds with identified boundaries.

Abstract

The question of graviton cloning in the context of the bulk/boundary correspondence is considered. It is shown that multi-graviton theories can be obtained from products of large-N CFTs. No more than one interacting massless graviton is possible. There can be however, many interacting massive gravitons. This is achieved by coupling CFTs via multi-trace marginal or relevant perturbations. The geometrical structure of the gravitational duals of such theories is that of product manifolds with their boundaries identified. The calculational formalism is described and the interpretation of such theories is discussed.