Eigenvalue inequalities in terms of Schatten norm bounds on differences of semigroups, and application to Schroedinger operators

We develop a new method for obtaining bounds on the negative eigenvalues of self-adjoint operators B in terms of a Schatten norm of the difference of the semigroups generated by A and B, where A is an operator with non-negative spectrum. Our method is based on the application of the Jensen identity of complex function theory to a suitably constructed holomorphic function, whose roots are in one-to-one correspondence with the negative eigenvalues of B. Applying our abstract results, together with bounds on Schatten norms of semigroup differences obtained by Demuth and Van Casteren, to Schroedinger operators, we obtain inequalities on moments of the sequence of negative eigenvalues, which are different from the Lieb-Thirring inequalities.