Title Information
Title
Singularities of Scattering Amplitudes: Symbol Letters, Cluster Adjacency, and Plabic Graphs
Type of Resource (primo)
dissertations
Name: Personal
Name Part
Mago Trejo, Jorge Leonardo
Role
Role Term: Text
creator
Name: Personal
Name Part
Volovich, Anastasia
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Jevicki, Antal
Role
Role Term: Text
Reader
Name: Personal
Name Part
Gates, Sylvester James
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Physics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2022
Physical Description
Extent
, None p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2022
Genre (aat)
theses
Abstract
In this thesis, we present a study of the singularity structure of scattering amplitudes in maximally supersymmetric Yang-Mills (N=4 SYM). We first consider the cluster adjacency properties of the singularities, and later we discuss a method to generate symbol letters from plabic graphs. We start our discussion by making use of the Sklyanin Poisson bracket on Gr(4,n) to investigate pair-wise cluster adjacency of singularities of rational Yangian invariants in N=4 SYM, and to establish that the n-point one-loop NMHV ratio function satisfies Steinmann cluster adjacency. We also present a series of conjectures about cluster adjacency. We continue our study of Yangian invariants in N=4 SYM by classifying all positive n-particle N^kMHV Yangian invariants in the theory with n=5k. We show that this problem is equivalent to that of enumerating plane cactus graphs with k pentagons and use this to enumerate the cyclic classes of these invariants. We provide an alternative (but equivalent) classification by showing that a product of k five-brackets with disjoint sets of indices is a positive Yangian invariant if and only if the sets are all weakly separated. Finally, we suggest an algorithm for computing symbol alphabets from plabic graphs by solving matrix equations of the form C Z = 0 to associate functions on Gr(m,n) to parameterizations of certain cells of Gr(k,n) indexed by plabic graphs. For m=4 and n=8 we show that this association precisely reproduces the 18 algebraic symbol letters of the two-loop NMHV eight-particle amplitude from four plabic graphs. We also show that it is possible to obtain all rational symbol letters by solving matrix equations of the form C Z = 0 if one allows C to be an arbitrary cluster parameterization of the top cell of Gr_+(n-4,n). We finish our discussion by identifying sets of parameterizations of the top cell of Gr_+(5,9) for which the solutions produce all of (and only) the cluster variable letters of the two-loop nine-particle NMHV amplitude, and identify plabic graphs from which all of its algebraic letters originate.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01063025")
Topic
Physics
Subject
Topic
scattering amplitudes
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01012104")
Topic
Mathematical physics
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01763173")
Topic
Cluster algebras
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01139038")
Topic
Supersymmetry
Subject
Topic
Yang-Mills Theory
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20220706