Twistors, strings and supersymmetric gauge theories

Abstract

This thesis is concerned with the study of scattering amplitudes in four-dimensional conformal field theories, more particularly the N=4 super-Yang-Mills theory. We study this theory first at tree level by using twistor space techniques and review the twistor string models that were proposed to describe it. Then, we turn to the issue of iteration relations and all loop ansatze for scattering amplitudes. We review the unitarity method for computing scattering amplitudes and discuss the Wilson loop--scattering amplitude duality that was inspired by the strong-coupling prescription of Alday and Maldacena for scattering amplitudes. We describe in some detail the computation of a two-loop six-point scattering amplitude and its surprising equality to the polygonal Wilson loop.

PhD thesis, 162 pages. Does not include discussion of and references to some recent work done after the submission of the thesis manuscript. v2 added reference, minor changes

References in corpus (20)

• New Relations for Gauge-Theory Amplitudes
• The Two-Loop Six-Gluon MHV Amplitude in Maximally Supersymmetric Yang-Mills Theory
• Three-Loop Superfiniteness of N=8 Supergravity
• Maximally Supersymmetric Planar Yang-Mills Amplitudes at Five Loops
• The hexagon Wilson loop and the BDS ansatz for the six-gluon amplitude
• Strong-coupling expansion of cusp anomaly and gluon amplitudes from quantum open strings in AdS_5 x S^5
• Sharpening The Leading Singularity
• Lectures on Twistor Strings and Perturbative Yang-Mills Theory
• Introduction to AdS-CFT
• A mini-course on topological strings
• Untwisting the twistor superstring
• Infrared Limit of Gluon Amplitudes at Strong Coupling
• On the structure of scattering amplitudes in N=4 super Yang-Mills and N=8 supergravity
• Scattering amplitudes in strongly coupled N=4 SYM from semiclassical strings in AdS
• On the Factorisation of the Connected Prescription for Yang-Mills Amplitudes
• A Note on Graviton Amplitudes for New Twistor String Theories
• Gluon scattering in $\mathcal{N}=4$ Super Yang-Mills at finite temperature
• Gluon Scattering in Deformed N=4 SYM
• $R^4$ terms in supergravity and M-theory
• One-loop N=8 Supergravity Amplitudes from MHV Diagrams