Integrating the full four-loop negative geometries and all-loop ladder-type negative geometries in ABJM theory

Abstract: The decomposition of the four-point ABJM amplituhedron into negative geometries produces compact integrands of logarithmic of amplitudes such that the infrared divergence only comes from the last loop integration, from which we can compute the cusp anomalous dimension of the ABJM theory. In this note, we integrate $L-1$ loop momenta of the $L$-loop negative geometries for all four-loop negative geometries and a special class of all-loop ladder-type negative geometries by a method based on Mellin transformation, and from these finite quantities we extract the corresponding contribution to the cusp anomalous dimension. We find that the infrared divergence of a box-type negative geometry at $L=4$ is weaker than other negative geometries, then only tree-type negative geometries contribute to the cusp anomalous dimension at $L=4$. For the all-loop ladder-type negative geometries, we prove and conjecture some recursive structures as integral equations in Mellin space and find that they cannot contribute zeta values like $\zeta_3,\zeta_5$ to the cusp anomalous dimension.