# Double field theory as the double copy of Yang-Mills theory

#### Double field theory as the double copy of Yang-Mills theory

- Event time: 2:00pm until 3:00pm
- Event date: 23rd November 2022
- Speaker: Felipe Diaz Jaramillo (Humboldt Universität Berlin )
- Location: Higgs Centre Seminar Room, Room 4305, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

The Bern-Carrasco-Johansson (BCJ) double copy in scattering amplitudes states that exchanging colour information by kinematic information in Yang-Mills (YM) amplitudes leads to gravity amplitudes. In this talk, based on the BCJ double copy, I will establish a perturbative relation at the level of the action between YM and a reformulation of gravity (+B-field and dilaton), called Double Field Theory (DFT). I will present two approaches to do this: the first one is a simple colour-kinematic substitution in the YM action that yields the gauge invariant action of DFT to quadratic order, and a gauge-fixed version at cubic order. The second approach is based on strongly homotopy Lie algebras. These mathematical structures encode the information of perturbative field theories and, in particular, the algebra that describes YM exhibits a manifest colour-kinematic split. I will show that, in the spirit of the BCJ construction, replacing colour by kinematics at the algebraic level reproduces gauge invariant DFT to cubic order in fields. Additionally, l will discuss how the gauge transformations of DFT, called generalised diffeomorphisms, and their corresponding gauge algebra, arise from the kinematic building blocks of YM theory.

#### Event resources

### About Particle Physics Theory seminars

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..