On soft singularities at three loops and beyond

Understand

We report on further progress in understanding soft singularities of massless gauge theory scattering amplitudes.

• Recently, a set of equations was derived based on Sudakov factorization, constraining the soft anomalous dimension matrix of multi-leg scattering amplitudes to any loop order, and relating it to the cusp anomalous dimension.
• The minimal solution to these equations was shown to be a sum over color dipoles.
• Here we explore potential contributions to the soft anomalous dimension that go beyond the sum-over-dipoles formula.