We prove in this paper resolvent estimates for the boundary values of resolvents of selfadjoint operators on a Krein space: if H is a selfadjoint operator on a Krein space H, equipped with the Krein scalar product 〈·|·〉, A is the generator of a C0−group on H and I ⊂ R is an interval such that: 1) H admits a Borel functional calculus on I, 2) the spectral projection 1lI (H) is positive in the Kr...

among the therapeutic options for achalasia are pneumatic dilatation (pd), an appropriate long-term therapy, and botulinum toxin injection (bt) that is a relatively short-term therapy. this study aimed to compare therapeutic effect of repetitive pneumatic dilation with a combined method (botulinum toxin injection and pneumatic dilation) in a group of achalasia patients who are low responder to ...

the objective of this paper is to establish a complete characterization of multiwavelet packets associated with matrix dilation on general lattices $gamma$ in $mathbb r^d$ by virtue of time-frequency analysis, matrix theory and operator theory.

We continue the spectral analysis of differential operators with complex coefficients, extending some results for Sturm-Liouville to higher order operators. give conditions essential spectrum be empty, and operator have compact resolvent. Conditions are given on coefficients resolvent Hilbert-Schmidt. These new even real i.e., selfadjoint case. Asymptotic is a central tool. See also https://ejd...

Let $$(Lv)(t)=sum^{n} _{i,j=1} (-1)^{j} d_{j} left( s^{2alpha}(t) b_{ij}(t) mu(t) d_{i}v(t)right),$$ be a non-selfadjoint differential operator on the Hilbert space $L_{2}(Omega)$ with Dirichlet-type boundary conditions. In continuing of papers [10-12], let the conditions made on the operator $ L$ be sufficiently more general than [11] and [12] as defined in Section $1$. In this paper, we estim...