Those are not even continuous vector fields and don’t even preserve the manifold structure of the spacetime. So not sure why they are “symmetries”. If you are allowed those kinds of vector fields then might as well take a delta function vector field and call it “ultra soft hair”!
I wish I had a geometric understanding of these extensions to the bms algebra. I know their charge integrals are finite so something makes *algebraic* sense, but I have no idea what it corresponds to geometrically.
Kartik Prabhu
There is nothing going on with these extended “symmetries”. If you give me a random thing to call a symmetry I can easily make up a charge formula for you.