Title Information
Title
Scattering amplitudes in N=4 SYM and N=8 SUGRA
Name: Personal
Name Part
Wen, Congkao
Role
Role Term: Text
creator
Origin Information
Copyright Date
2011
Physical Description
Extent
xviii, 146 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2011)
Name: Personal
Name Part
Volovich, Abastasia
Role
Role Term: Text
Director
Name: Personal
Name Part
Jevicki, Antal
Role
Role Term: Text
Reader
Name: Personal
Name Part
Tan, Chung-I
Role
Role Term: Text
Reader
Name: Personal
Name Part
Marcus, Spradlin
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Physics
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
The main subject of this thesis is scattering amplitudes in N=4 super-Yang-Mills theory (SYM) and N=8 super-gravity theory (SUGRA). We study several aspects of the scattering amplitudes of these two theories using modern techniques. After the introductory chapter, we apply these methods to study the scattering amplitudes both in N=4 SYM and N=8 SUGRA. We first study two dual formulations of N=4 SYM, namely the Arkani-Hamed et al Grassmannian formulation and Witten's twistor string theory. We present a new, explicit formula for all tree-level amplitudes in N=4 SYM. The formula is written as a certain contour integral of the connected prescription of Witten's twistor string, expressed in link variables. A very simple and interesting deformation of the integrand gives directly the Grassmannian integrand proposed together with the explicit contour of integration.Then we calculate for the first time the five-point three-loop amplitudes of N=4 SYM using the leading singularity method. Using the method of obstructions we numerically evaluate two previously unfixed coefficients which appear in the three-loop BDS ansatz. After the study of N=4 SYM, we turn our journey to N=8 SUGRA by first presenting and proving a new formula for MHV scattering amplitude in SUGRA. Some of interesting features of the formula set it apart as being significantly different from many more familiar formulas. We then present an algorithm for writing down explicit formulas for all tree amplitudes in N=8 SUGRA, obtained from solving the supersymmetric on-shell recursion relations. The formula is patterned after one recently obtained for all tree amplitudes in N=4 SYM which involves nested sums of dual superconformal invariants. We find that all graviton amplitudes can be written in terms of exactly the same structure of nested sums with two modifications. To illustrate the procedure we give explicit closed-form formulas for all NMHV, NNMHV and NNNMV gravity superamplitudes. The obtained results are further simplified by applying bonus relations between gravity amplitudes, which arise from the soft behavior of tree-level gravity amplitude.
Subject
Topic
string theory
Subject
Topic
scattering amplitude
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1085105")
Topic
Quantum field theory
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1135293")
Topic
String models
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1139038")
Topic
Supersymmetry
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20111003
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0KS6PTK
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In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations