A regularity result for the bound states of $N$-body Schrodinger operators: Blow-ups and Lie manifolds

We prove regularity estimates for the eigenfunctions of Schrodinger type operators whose potentials have inverse square singularities and uniform radial limits at infinity. In particular, the usual $N$-body operators are covered by our result; in that case, the weight is in terms of the (euclidean) distance to the collision planes. The technique of proof is based on blow-ups and Lie manifolds. More precisely, we first blow-up the spheres at infinity of the collision planes to obtain the Georgescu-Vasy compactification and then we blow-up the collision planes. We carefully investigate how the Lie manifold structure and the associated data (metric, Sobolev spaces, differential operators) change with each blow-up. Our method applies also to higher order operators and matrices of scalar operators.