I suspect this question is rather naive, but here goes. I have a set of basis functions that I suspect are eigenfunctions of an unknown differential operator (due to some results I've seen in some of my research). I have no idea what differential operator they correspond to.
Is there some general procedure one can follow to work out what the differential operator is, given the suspected eigenfunctions? If not, is there some procedure one can follow to figure out some properties of the differential operator of which I suspect my basis functions are eigenfunctions?
I'd appreciate some suggestions on where to start. Thank you.