https://iopscience.iop.org/article/10.3847/1538-4357/ad2f99

In March 2020, we published a paper titled "Unified Field Theory for Gravity and Electromagnetism and Its Explanation for Dark Matter Observations," which explains how electromagnetic waves or photons can have a gravitational effect similar to baryonic matter.

https://zenodo.org/records/4057270#.YPOcr0wpDIW

In our paper, we derived equations for the force between photons or between a photon and matter with mass. You can find the details of this relationship.

https://zenodo.org/records/4541280#.YPOcfUwpDIW

The conclusion in Mr. Wang's paper about the nonzero mass of photons supports and enhances the "Unified Field Theory for Gravity and Electromagnetism." The empirical evidence of photon mass provides a basis for further exploration of gravitational interactions involving photons, aligning with the unified field theory's broader claims about the interplay between gravity and electromagnetism.

Dark matter is light (gravitational effect of EM waves, Photons).