14:00
Twistor-space gauge-theory amplitudes from off-shell functionals
Abstract
I will present a pair of off-shell functionals in position space, localized on the self-dual and the anti-self-dual planes which naturally give the Parke-Taylor denominator. These can therefore be used:
i) to compute scattering amplitudes of particles with different spins and helicities; and
ii) develop a Lagrangian description.
Using Witten's half-Fourier transform, I will express these functionals in twistor space and present the kernels in a closed compact form. For even multiplicities, I will show how to obtain this form geometrically which than then be “folded” to get the one-less odd-multiplicity result.
11:30
Chiral fields for massive higher spins
Abstract
I will review some recent developments in effective field theory of composite higher-spin particles, namely, Zinoviev's massive gauge symmetry and
the new chiral-field approach. The latter approach was inspired by a simple spinor-helicity structure first singled out by Arkani-Hamed, Huang and Huang, which encodes the higher-spin information of two massive particles. It turned out to be persistent in tree-level amplitudes with any number of additional identical-helicity gluons or gravitons, leading to the discovery of the chiral-field approach. I will mention the applications of massive higher-spin scattering amplitudes to classical gravitational dynamics of rotating black holes.