Here's a series of lectures given by the famous Dominic Joyce on some topics of interest to mathematical physics. Anyone who knows some basic differential geometry can learn a few things from this.
https://qgm.au.dk/video/mc/riemannian-holonomy-groups-gauge-theory-and-instanton-moduli-spaces/index.html
Feel free to share other good videos with /sci/, maybe we can actually discuss stuff other than covid.