Factorization by Lattice Homomorphisms.
Fermi Golden Rule, Feshbach Method and embedded point spectrum
A method to study the embedded point spectrum of self-adjoint operators is described. The method combines the Mourre theory and the Limiting Absorption Principle with the Feshbach Projection Method. A more complete description of this method is contained in a joint paper with V. Jakić, where it is applied to a study of embedded point spectrum of Pauli-Fierz Hamiltonians.
Feynman's operational calculi: using Cauchy's integral formula.
First results on spectrally bounded operators
A linear mapping T from a subspace E of a Banach algebra into another Banach algebra is defined to be spectrally bounded if there is a constant M ≥ 0 such that r(Tx) ≤ Mr(x) for all x ∈ E, where r(·) denotes the spectral radius. We study some basic properties of this class of operators, which are sometimes analogous to, sometimes very different from, those of bounded operators between Banach spaces.
Floquet operators without absolutely continuous spectrum
Fonction spectrale d'opérateurs non elliptiques
Formeln für Pole der Resolvente und den Radius eines wesentlichen Spektrums.
Fredholm, Riesz and local spectral theory of multipliers.
Funktionalkalküle in mehreren Veränderlichen für stetige lineare Operatoren auf Banachräumen.