NEW THEORY. “In our new theory on DPs, we have introduced a new mathematical formulation called the Clebsch dual field, and some of the important outcomes derived from the formulation will be used in our arguments without detailed explanation; hence, we reserve the Method section until the end to give a revised concise explanation as background information for interested readers.” (DP = dressed photon).
https://www.mdpi.com/2073-8994/12/8/1244/htm