Celestial operator products from the worldsheet

Understand

We compute the operator product expansions of gluons and gravitons in celestial CFT from the worldsheet OPE of vertex operators of four-dimensional ambitwistor string theories.

• Remarkably, the worldsheet OPE localizes on the short-distance singularity between vertex operator insertions which in turn coincides with the OPE limit of operator insertions on the celestial sphere.
• The worldsheet CFT dynamically produces known celestial OPE coefficients -- as well as infinite towers of SL$(2,\mathbb{R})$ descendant contributions to the celestial OPE -- without any truncations or approximations.
• We obtain these results for all helicities and incoming/outgoing configurations.