Topics in Operator Theory

In Memory of Constantin Apostol.- Constantin Apostol List of Publications.- On a Spectral Equivalence of Operators.- Fredholm Properties of Band Matrices and Dichotomy.- A Note on the Algebra Generated by a Subnormal Operator.- Extreme Points in the Set of Contractive Intertwining Dilations.- Extreme Points in Quotients of Operator Algebras.- On the Four Block Problem, I.- Variation of the Point Spectrum under Compact Perturbations.- Bimodules of Nest Subalgebras of von Neumann Algebras.- Stability of Invariant Lagrangian Subspaces I.- Products of Kernel Functions and Module Tensor Products.- Spectral Capacities in Quotient Fret Spaces.- A Note on Quasidiagonal Operators.