Conveners
Parallel Sesion: Gravity and Gauge Theories
- Calum Robson (Durham University)
Isobel Nicholson
(University of Edinburgh)
12/01/2017, 09:00
The "double copy" expresses gravity as the square of Yang-Mills. This elegant property was originally found for amplitudes, since it has been proven to tree level it must also be true for classical theory as well. Excitingly, this means that black holes and other exact solutions to general relativity can be described without needing perturbation theory. This talk will explore the relationship...
Mr
Andrew Bond
(University of Sussex)
12/01/2017, 09:25
Ultraviolet fixed points of the renormalisation group flow allow one to define quantum field theories which are valid up to arbitrarily high energies. However, finding fixed points is a difficult problem in general as one has an infinite number of couplings to deal with. In this talk I will discuss how restricting to the case of weakly coupled four-dimensional gauge theories allows for a...
Mr
Scott Melville
(Imperial College London)
12/01/2017, 09:50
Many quantum field theories are only well-defined at low energies - with a breakdown of unitarity above some energy cutoff. If there is a physically sensible way to introduce new degrees of freedom which restore unitarity, then this apparent breakdown needn't worry us - we say that the original theory admits a *UV completion*. However, if it is **not** possible to UV complete the theory, this...
Mr
Joseph Farrow
(Durham University)
12/01/2017, 10:15
I will introduce the language of on-shell diagrams for calculating scattering amplitudes via BCFW recursion in $\mathcal{N} = 4$ super Yang Mills theory, and then explain how they can be extended to $\mathcal{N} = 8$ supergravity. I will describe how this approach relates scattering amplitudes to the Grassmannian Gr$(k,n)$, a purely geometric object describing the space of $k$ planes in $n$...
