#### Double-soft limits for gauge and gravity amplitudes

- Event time: 2:00pm
- Event date: 16th December 2015
- Speaker: Tristan McLoughlin (Trinity College, Dublin)
- Location: Higgs Centre Seminar Room, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

We will discuss the double-soft limit of gluon and graviton amplitudes in four dimensions at tree level. In general this limit is ambiguous and we introduce two natural ways of taking it: A consecutive double-soft limit where one particle is taken soft before the other and a simultaneous limit where both particles are taken soft uniformly. The resulting formulae generalise the universal behaviour of single-soft limits. We will then use these results to discuss the algebraic structure of the symmetries of gravity and Yang-Mills S-matrices.

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..