-local unconditional structure of Banach spaces
symmetric Schrödinger operators: reality of the perturbed eigenvalues.
P-adic semi-Fredholm operators and measures of non-compactness.
Paley-Wiener Type Theorems by Transmutations.
Parallel methods in image recovery by projections onto convex sets
Parametrization and Schur algorithm for the integral representation of Hankel forms in T-square
Partial inner product spaces of entire functions
Partial isometries and EP elements in rings with involution.
Partitions of spectral sets
Periodic Schrödinger Operators with (Non-Periodic) Magnetic and Electric Potentials.
Periodic solutions of partial differential equations with hysteresis
Periodic solutions to abstract differential equations
Perron root of a convex combination of a positive kernel and its adjoint
Perron-Frobenius and Krein-Rutman theorems for tangentially positive operators
We study several aspects of a generalized Perron-Frobenius and Krein-Rutman theorems concerning spectral properties of a (possibly unbounded) linear operator on a cone in a Banach space. The operator is subject to the so-called tangency or weak range assumptions implying the resolvent invariance of the cone. The further assumptions rely on relations between the spectral and essential spectral bounds of the operator. In general we do not assume that the cone induces the Banach lattice structure into...
Pertubation of Operators and Applications to Frame Theory.
Perturbation and spectral discontinuity in Banach algebras
We extend an example of B. Aupetit, which illustrates spectral discontinuity for operators on an infinite-dimensional separable Hilbert space, to a general spectral discontinuity result in abstract Banach algebras. This can then be used to show that given any Banach algebra, Y, one may adjoin to Y a non-commutative inessential ideal, I, so that in the resulting algebra, A, the following holds: To each x ∈ Y whose spectrum separates the plane there corresponds a perturbation of x, of the form z =...
Perturbation Classes of Semi-Fredholm Operators.
Perturbation de générateurs infinitésimaux du type «changement de temps»
On obtient un théorème général concernant la perturbation multiplicative par un opérateur (linéaire borné, mais pas forcément d’inverse borné), du générateur d’un semi-groupe fortement continu sur un espace de Banach. On en déduit un résultat intimement lié au changement de temps dans les processus de Markov, qui étend un théorème de Dorroh (et résout par l’affirmative la seule situation qui restait en doute dans le contexte du théorème de Dorroh cité). Comme exemple d’autres possibilités d’application,...
Perturbation des résolvantes et des semi-groupes par une mesure de Radon positive.
Perturbation of a Fredholm complex by inessential operators.