Nastase, H., Rojas, F., & Rubio, C. (2022). Celestial IR divergences in general mostsubleadingcolor gluon and gravity amplitudes. J. High Energy Phys., (1), 136.
Abstract: Gluon amplitudes at mostsubleading order in the 1/N expansion share a remarkable simplicity with graviton amplitudes: collinear divergences are completely absent in both and, as a consequence, their full IR behavior arises from soft gluon/graviton exchange among the external states. In this paper we study the effect of allloop IR divergences of celestial mostsubleading color gluon amplitudes and their similarities with the celestial gravity case. In particular, a simple celestial exponentiation formula for the dipole part can be written. We also analize how this exponentiation is modified by nondipole contributions. Finally we also show that, in the Regge limit, the soft factor satisfies the KnizhnikZamolodchikov equation hinting at the possibility that, in this limit, an effective WessZuminoWitten model would describe the dynamics of the infrared sector.
