Variation de la phase de diffusion et distribution des résonances
Variational approximation methods for eigenvalues. Convergence theorems
Variational characterization of eigenvalues of a non-symmetric eigenvalue problem governing elastoacoustic vibrations
Small amplitude vibrations of an elastic structure completely filled by a fluid are considered. Describing the structure by displacements and the fluid by its pressure field one arrives at a non-selfadjoint eigenvalue problem. Taking advantage of a Rayleigh functional we prove that its eigenvalues can be characterized by variational principles of Rayleigh, minmax and maxmin type.
Variational semi-regularity and norm convergence.
Variations on a theme of Beurling.
Variations on Yano's extrapolation theorem.
We give very short and transparent proofs of extrapolation theorems of Yano type in the framework of Lorentz spaces. The decomposition technique developed in Edmunds-Krbec (2000) enables us to obtain known and new results in a unified manner.
Vasilescu-Martinelli formula for operators in Banach spaces
We prove a formula for the Taylor functional calculus for functions analytic in a neighbourhood of the splitting spectrum of an n-tuple of commuting Banach space operators. This generalizes the formula of Vasilescu for Hilbert space operators and is closely related to a recent result of D. W. Albrecht.
Vector and operator trapezoidal type inequalities for continuous functions of selfadjoint operators in Hilbert spaces.
Vector ergodic theorem in .
Vector-valued ergodic theorems for multiparameter additive processes
Let X be a reflexive Banach space and (Ω,Σ,μ) be a σ-finite measure space. Let d ≥ 1 be an integer and T=T(u):u=(, ... ,, ≥ 0, 1 ≤ i ≤ d be a strongly measurable d-parameter semigroup of linear contractions on ((Ω,Σ,μ);X). We assume that to each T(u) there corresponds a positive linear contraction P(u) defined on ((Ω,Σ,μ);ℝ) with the property that ∥ T(u)f(ω)∥ ≤ P(u)∥f(·)∥(ω) almost everywhere on Ω for all f ∈ ((Ω,Σ,μ);X). We then prove stochastic and pointwise ergodic theorems for a d-parameter...
Vector-valued ergodic theorems for multiparameter Additive processes II
Previously we obtained stochastic and pointwise ergodic theorems for a continuous d-parameter additive process F in L₁((Ω,Σ,μ);X), where X is a reflexive Banach space, under the condition that F is bounded. In this paper we improve the previous results by considering the weaker condition that the function is integrable on Ω.
Vector-valued transference and maximal ergodic theory in UMD-valued function spaces.
Verwandte Operatoren.
Von Neumann operators are reflexive.