Recursion Relations, Generating Functions, and Unitarity Sums in N=4 SYM Theory release_vyuaw3lsgrernfzhizkatowsra

by Henriette Elvang, Daniel Z. Freedman, Michael Kiermaier

Released as a article .



We prove that the MHV vertex expansion is valid for any NMHV tree amplitude of N=4 SYM. The proof uses induction to show that there always exists a complex deformation of three external momenta such that the amplitude falls off at least as fast as 1/z for large z. This validates the generating function for n-point NMHV tree amplitudes. We also develop generating functions for anti-MHV and anti-NMHV amplitudes. As an application, we use these generating functions to evaluate several examples of intermediate state sums on unitarity cuts of 1-, 2-, 3- and 4-loop amplitudes. In a separate analysis, we extend the recent results of arXiv:0808.0504 to prove that there exists a valid 2-line shift for any n-point tree amplitude of N=4 SYM. This implies that there is a BCFW recursion relation for any tree amplitude of the theory.
In text/plain format

Archived Files and Locations

application/pdf  557.6 kB
file_gtpyd3mce5dw5fskx3egpflw4u (archive)
Read Archived PDF
Type  article
Stage   accepted
Date   2008-12-20
Version   v2
Language   en ?
arXiv  0808.1720v2
Work Entity
access all versions, variants, and formats of this works (eg, pre-prints)
Catalog Record
Revision: 6761742b-d117-46a7-8391-220f6465526a