Exacting N=4 Superconformal Symmetry
Abstract
Tree level scattering amplitudes in N=4 super Yang-Mills theory are almost, but not exactly invariant under the free action of the N=4 superconformal algebra. What causes the non-invariance is the holomorphic anomaly at poles where external particles become collinear. In this paper we propose a deformation of the free superconformal representation by contributions which change the number of external legs. This modified classical representation not only makes tree amplitudes fully invariant, but it also leads to additional constraints from symmetry alone mediating between hitherto unrelated amplitudes. Moreover, in a constructive approach it appears to fully constrain all tree amplitudes when combined with dual superconformal alias Yangian symmetry.
Cite
@article{arxiv.0905.3738,
title = {Exacting N=4 Superconformal Symmetry},
author = {Till Bargheer and Niklas Beisert and Wellington Galleas and Florian Loebbert and Tristan McLoughlin},
journal= {arXiv preprint arXiv:0905.3738},
year = {2009}
}
Comments
47 pages. v2: minor corrections, clarifications and additions; algebraic derivation of {S,Sbar}=K, v3: section 4.4 restored (it was dropped by mistake in v2), minor corrections, to appear in JHEP