|DATE||August 20 (Mon), 2018|
|INSTITUTE||Institut Astrophysique de Paris|
|TITLE||Deforming massive theories|
Cohomological techniques based on BRST symmetry have proved invaluable for classifying consistent interactions in gauge theories. In this talk I will describe the application of this idea to massive field theories, which are made gauge-invariant by the introduction of Stuckelberg fields. As a first application, we show that the free theory of a collection of massive vectors can be uniquely “deformed” to yield the cubic and quartic interaction vertices of massive Yang-Mills theory. Similarly, starting with a Fierz-Pauli graviton on a maximally symmetric space, we prove that the cohomological method is able to reproduce the consistent cubic vertices of ghost-free massive gravity. The formalism further sheds light on the characterization of Stuckelberg gauge theories, by demonstrating for instance that the gauge algebra of such models is Abelian and that they admit a Born-Infeld type formulation in which the action is simply a combination of gauge-invariant structures.