Journal of High Energy Physics (Apr 2021)
Symbol alphabets from plabic graphs II: rational letters
Abstract
Abstract Symbol alphabets of n-particle amplitudes in N $$ \mathcal{N} $$ = 4 super-Yang-Mills theory are known to contain certain cluster variables of G(4, n) as well as certain algebraic functions of cluster variables. The first paper arXiv:2007.00646 in this series focused on n = 8 algebraic letters. In this paper we show that it is possible to obtain all rational symbol letters (in fact all cluster variables) 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 G+(n−4, n).
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