Asymptotic behavior of eigenvalues of Schr\"odinger type operators with   degenerate kinetic energy
  We study the eigenvalues of Schr\"odinger type operators $T +   \lambda V$ and their asymptotic behavior in the small coupling limit   $\lambda \to 0$, in the case where the symbol of the kinetic energy,   $T(p)$, strongly degenerates on a non-trivial manifold of codimension one. 
Christian Hainzl, Robert Seiringer