Weyl asymptotics for tensor products of operators and Dirichlet divisors
  We study the counting function of the eigenvalues for tensor products of operators, and their perturbations, in the context of Shubin classes and closed manifolds. We emphasize connections with problems of analytic number theory, concerning in particular generalized Dirichlet divisor functions. 
Todor Gramchev, Stevan Pilipovic, Luigi Rodino, and Jasson Vindas
math.SP