Publication details for Valentin [Valya] KhozeAbel, S., Forste, S. & Khoze, V.V. (2007). Scattering amplitudes in strongly coupled N = 4 SYM from semiclassical strings in AdS. Journal of high energy physics 2008(2): 042.
- Publication type: Journal Article
- ISSN/ISBN: 1029-8479
- DOI: 10.1088/1126-6708/2008/02/042
- Keywords: Supersymmetric gauge theory, Extended supersymmetry, Gauge-gravity correspondence.
- Further publication details on publisher web site
Author(s) from Durham
Very recently in  Alday and Maldacena gave a string theory prescription for computing (all) planar amplitudes in Script N = 4 supersymmetric gauge theory at strong coupling using the AdS/CFT correspondence. These amplitudes are determined by a classical string solution and contain a universal exponential factor involving the action of the classical string. On the gauge theory side, expressions for perturbative amplitudes at strong coupling were previously proposed only for specific helicities of external particles — the maximally helicity violating or MHV amplitudes. These follow from the exponential ansatz of Bern, Dixon and Smirnov  for MHV amplitudes in Script N = 4 SYM. In this paper we examine the amplitudes dependence on helicities and particle-types of external states. We consider the prefactor of string amplitudes and give arguments suggesting that the prefactor at strong coupling should be the same as the Yang-Mills tree-level amplitude for the same process. This implies that scattering amplitudes in Script N = 4 SYM simplify dramatically in the strong coupling limit. It follows from our proposal that in this limit all (MHV and non-MHV) n-point amplitudes are given by the (known) tree-level Yang-Mills result times the helicity-independent (and particle-type-independent) universal exponential.