# Triangulation of 2-loop MHV amplituhedron from sign flips

Kojima, Ryota (0000 0004 1763 208X, grid.275033.0, Department of Particle and Nuclear Physics, SOKENDAI (The Graduate University for Advanced Studies), Tsukuba, Ibaraki, 305-0801, Japan) (0000 0001 2155 959X, grid.410794.f, KEK Theory Center, Tsukuba, Ibaraki, 305-0801, Japan)

12 April 2019

Abstract: In this paper, we consider the triangulation of the 2-loop MHV amplituhedron from “sign flip” definition. Using the isomorphism between the m = 2 , k = 2 tree amplituhedron and the 1-loop MHV physical amplituhedron, we found the direct triangulation of the 2-loop MHV amplituhedron from sign flips. This triangulation is different from the BCFW triangulation because of the structure of the cells. And we also found a formula of the canonical form of the n -point 2-loop MHV amplituhedron. This formula looks like a 2-loop version of the Kermit representation of the 1-loop MHV amplitude. We checked that the sum of these cells is consistent with the BCFW up to at least 22-pt numerically.

Published in: JHEP 1904 (2019) 085 DOI: 10.1007/JHEP04(2019)085
arXiv: 1812.01822