Algebraic Sum of Unbounded Normal Operators and the Square Root Problem of Kato

We prove that the algebraic sum of unbounded normal operators satisfies the square root problem of Kato under appropriate hypotheses. As application, we consider perturbed Schrodinger operators.Comment: 9 page

Existence of Pseudo Almost Periodic Solutions to Some Classes of Partial Hyperbolic Evolution Equations

The paper examines the existence of pseudo almost periodic solutions to some classes of partial hyperbolic evolution equations. Namely, sufficient conditions for the existence and uniqueness of pseudo almost periodic solutions to those classes of hyperbolic evolution equations are given. Applications include the existence of pseudo almost periodic solutions to the transport and heat equations with delay.Comment: 12 page