English

Symbol Alphabets from Plabic Graphs III: n=9

High Energy Physics - Theory 2021-06-04 v1

Abstract

Symbol alphabets of n-particle amplitudes in N=4 super-Yang-Mills theory are known to contain certain cluster variables of Gr(4,n) as well as certain algebraic functions of cluster variables. In this paper we solve the C Z = 0 matrix equations associated to several cells of the totally non-negative Grassmannian, combining methods of arXiv:2012.15812 for rational letters and arXiv:2007.00646 for algebraic letters. We identify 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 2-loop nine-particle NMHV amplitude, and identify plabic graphs from which all of its algebraic letters originate.

Cite

@article{arxiv.2106.01406,
  title  = {Symbol Alphabets from Plabic Graphs III: n=9},
  author = {Jorge Mago and Anders Schreiber and Marcus Spradlin and Akshay Yelleshpur Srikant and Anastasia Volovich},
  journal= {arXiv preprint arXiv:2106.01406},
  year   = {2021}
}

Comments

14 pages, 4 figures

R2 v1 2026-06-24T02:46:05.463Z