A Density Theorem on the Eigenvalues of Spherically Symmetric Interior   Transmission Problem in Absorbing Medium
  We describe the asymptotic distribution of the eigenvalues of interior transmission problem in absorbing medium. We apply the Cartwright's theory and the technique from asymptotic periodic entire function theory. We find a Weyl's type of density theorem on counting the eigenvalues for spherically symmetric interior transmission problem in absorbing medium. 
Lung-Hui Chen
math.FA