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arXiv · 2305.17069

Landau Singularities of the 7-Point Ziggurat II

Luke Lippstreu·Marcus Spradlin·Akshay Yelleshpur Srikant·Anastasia Volovich
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Abstract

We solve the Landau equations to find the singularities of nine three-loop 7-point graphs that arise as relaxations of the graph studied in arXiv:2211.16425. Along the way we establish that $Y{-}\Delta$ equivalence fails for certain branches of solutions to the Landau equations. We find two graphs with singularities outside the heptagon symbol alphabet; in particular they are not cluster variables of ${\rm Gr}(4,7)$. We compare maximal residues of scalar graphs exhibiting these singularities to those in $\mathcal{N}=4$ super-Yang-Mills theory in order to probe their cancellation from its amplitudes.

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Luke Lippstreu, Marcus Spradlin, Akshay Yelleshpur Srikant, Anastasia Volovich. 2023-05-26. Landau Singularities of the 7-Point Ziggurat II. https://arxiv.org/abs/2305.17069

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