Seminar series
Date
Mon, 27 Apr 2009
Time
12:00 -
13:00
Location
L3
Speaker
Andrew Hodges
Organisation
Oxford
Abstract: The recent paper by Arkani-Hamed, Cachazo, Cheung and Kaplan on 'The S-matrix in Twistor Space' (hep-th/0903.2110v2) has envigorated the project of expressing scattering amplitudes for (supersymmetric) gauge theory and gravity entirely in terms of twistor geometry. I shall review these new developments of twistor diagram theory, with some illustrations of its computational value. I shall also emphasise the many outstanding problems in the formalism. One of these, which Arkani-Hamed has highlighted, is the asymmetry in the representation of the amplitudes and the 'spurious poles' that arise. So far, the twistor diagram formalism has simply reproduced the less than satisfactory features of the (supersymmetrised) BCFW recursion. I will outline some new twistor-geometric results which address and partially resolve this problem.