No triangles on the moduli space of maximally supersymmetric gauge theory

TL;DR

This paper demonstrates the absence of triangle coefficients in the one-loop amplitudes of maximally supersymmetric gauge theory on its moduli space, providing evidence for dual conformal symmetry from a field theory perspective.

Contribution

It proves, using both on-shell and off-shell methods, that triangle coefficients vanish at any point on the moduli space of maximally supersymmetric gauge theory.

Findings

No triangle coefficients in one-loop functions at any moduli space point.

Absence of rational terms in a class of Coulomb branch theories.

Supports dual conformal symmetry from field theory calculations.

Abstract

Maximally supersymmetric gauge theory in four dimensions has a remarkably simple S-matrix at the origin of its moduli space at both tree and loop level. This leads to the question what, if any, of this structure survives at the complement of this one point. Here this question is studied in detail at one loop for the branch of the moduli space parameterized by a vacuum expectation value for one complex scalar. Motivated by the parallel D-brane picture of spontaneous symmetry breaking a simple relation is demonstrated between the Lagrangian of broken super Yang-Mills theory and that of its higher dimensional unbroken cousin. Using this relation it is proven both through an on- as well as an off-shell method there are no so-called triangle coefficients in the natural basis of one-loop functions at any finite point of the moduli space for the theory under study. The off-shell method yields in addition absence of rational terms in a class of theories on the Coulomb branch which includes the special case of maximal supersymmetry. The results in this article provide direct field theory evidence for a recently proposed exact dual conformal symmetry motivated by the AdS/CFT correspondence.