RIGHT SEMIDEFINITE EIGENVALUE PROBLEMS

The relationships between various notions of completeness of eigenvectors and root vectors of the eigenvalue problem $Af=\lambda Bf$ are investigated. Here $A$ and $B$ are self-adjoint operators in Hilbert space with $B$ bounded and positive semidefinite, and with $A$ having compact resolvent.AMS 2000 Mathematics subject classification: Primary 47A75. Secondary 34B24; 35P10