Two-loop $D$-dimensional unitarity and dual-conformal symmetry

Abstract

In this talk we show that dual conformal symmetry has unexpected applications to Feynman integrals in dimensional regularization. Outside $4$ dimensions, the symmetry is anomalous, but still preserves the unitarity cut surfaces. This generally leads to differential equations whose RHS is proportional to $(d-4)$ and has no doubled propagators. The stabilizer subgroup of the conformal group leads to integration-by-parts (IBP) relations without doubled propagators. The above picture also suggested hints that led us to find a nonplanar analog of dual conformal symmetry.