15-16 December 2020
Centre for Particle Theory, Durham
Europe/London timezone

On the Lagrangian formulation of the double copy to cubic order

15 Dec 2020, 12:05
5m
Teams (Centre for Particle Theory, Durham)

Teams

Centre for Particle Theory, Durham

IPPP & Dept. Mathematical Sciences Durham University South Road Durham DH1 3LE

Speaker

Pietro Ferrero (University of Oxford)

Description

We investigate the Lagrangian formulation of the double-copy correspondence between gauge theories and gravity, up to the cubic order. Building on the definition of the double-copy field as a convolution of two vectors, we obtain free gravitational Lagrangians as products of two Yang-Mills Lagrangians, in a form amenable to be easily extended to the massive case. We discuss the origin of these results from tensionless strings and show the existence of gauge fixings that mix the two spin-one sectors and lead to an alternative, especially simple, version of the free Lagrangian. We then construct cubic vertices for the full double-copy multiplet, comprising a graviton, a two- form and a scalar particle, by means of the Noether procedure. Both at the free and at the cubic level the result gets uniquely fixed only upon imposing, on top of gauge invariance, a left-right Lorentz symmetry ruling contraction of indices among double-copy fields. Whereas the outcome nicely matches the cubic interactions of N = 0 supergravity, including the gauge-invariant coupling between the scalar particle and the two-form, such a twofold Lorentz symmetry seems to conflict with the perturbative reconstruction of space-time geometry.

Will you be pre-recording your talk? No
Are you happy for your talk to be recorded? No
Length of talk 3-5 minutes
Would you be interested in receiving feedback on your talk? Yes

Primary author

Pietro Ferrero (University of Oxford)

Co-author

Dario Francia

Presentation Materials