In this paper we develop a natural generalization of Schauder basis theory, we term operator-valued basis or simply ov-basis theory, using operator-algebraic methods. We prove several results for ov-basis concerning duality, orthogonality, biorthogonality and minimality. We prove that the operators of a dual ov-basis are continuous. We also dene the concepts of Bessel, Hilbert ov-basis and obta...

In this paper, we give some sufficient conditions under which perturbations preserve Hilbert frames and near-Riesz bases. Similar results are also extended to frame sequences, Riesz sequences and Schauder frames. It is worth mentioning that some of our perturbation conditions are quite different from those used in the previous literature on this topic.

We introduce multipulse multicarrier (MPMC) modulation, a wireless communication scheme that augments traditional singlepulse multicarrier systems by using multiple pulses at the transmitter and the receiver. The mathematical foundation of MPMC systems is established by the novel concept of multipulse Gabor Riesz bases. We adapt Zak-Fourier domain tools previously developed for multiwindow Gabo...

Recently we developed multiscale spaces of C piecewise quadratic polynomials relative to arbitrary polygonal domains Ω ⊂ R. These multiscale bases are weakly stable with respect to the L2 norm. In this paper we show that these bases form strongly stable Riesz bases for the Sobolev spaces Hs(Ω) with s ∈ (2, 5 2 ).

In recent investigation 8] concerning the asymptotic behavior of Gram Schmidt or-thonormalization procedure applied to the nonnegative integer shifts of a given function, the problem of determining whether or not such functions form a Riesz system in L 2 (IR +) arose. In this note, we provide a suucient condition to determine whether the nonnegative translates form a Riesz system on L 2 (IR +)....

in this paper we develop a natural generalization of schauder basis theory, we term operator-valued basis or simply ov-basis theory, using operator-algebraic methods. we prove several results for ov-basis concerning duality, orthogonality, biorthogonality and minimality. we prove that the operators of a dual ov-basis are continuous. we also dene the concepts of bessel, hilbert ov-basis and obt...

Related DatabasesWeb of Science You must be logged in with an active subscription to view this.Article DataHistorySubmitted: 14 September 2020Accepted: 11 August 2021Published online: 16 December 2021KeywordsRiesz spectral operator, infinite-dimensional linear port-Hamiltonian system, strongly continuous groupAMS Subject Headings35P10, 47B06, 47D06, 35L40Publication DataISSN (print): 0363-0129I...