Results 11 to 20 of about 714 (196)

K-Riesz bases and K-g-Riesz bases in Hilbert C∗-module [PDF]

Proyecciones (Antofagasta), 2023
This paper is devoted to studying the K-Riesz bases and the K-g-Riesz bases in Hilbert C∗-modules; we characterize the concept of K-Riesz bases by a bounded below operator and the standard orthonormal basis for Hilbert C∗-modules H. Also We give some properties and characterization of K-g-Riesz bases by a bounded surjective operator and g-orthonormal ...
El Amrani, Abdelkhalek, Rossafi, Mohamed, El Krouk, Tahar   +2 more
openaire   +3 more sources

A New Approach to Continuous Riesz Bases [PDF]

Journal of Sciences, Islamic Republic of Iran, 2013
This paper deals with continuous frames and continuous Riesz bases. We introduce continuous Riesz bases and give some equivalent conditions for a continuous frame to be a continuous Riesz basis.
A.A. Arefijamaal, R.A. Kamyabi Gol, R. Raisi Tousi, N. Tavallaei   +3 more
doaj   +2 more sources

Riesz bases and positive operators on Hilbert space [PDF]

International Journal of Mathematics and Mathematical Sciences, 2003
It is shown that a normalized Riesz basis for a Hilbert space H (i.e., the isomorphic image of an orthonormal basis in H) induces in a natural way a new, but equivalent, inner product on H in which it is an orthonormal basis, thereby extending the sense ...
James R. Holub
doaj   +2 more sources

Weaving Riesz Bases [PDF]

Journal of Fourier Analysis and Applications
This paper explores woven frames in separable Hilbert spaces with an initial focus on the finite-dimensional case. We begin by simplifying the problem to bases, for which we obtain a unique characterization. We establish a condition that is both necessary and sufficient for vector reconstruction, which applies to Fourier matrices.
C. Cabrelli, U. Molter, F. Negreira
openaire   +4 more sources

New Characterizations of Riesz Bases [PDF]

Applied and Computational Harmonic Analysis, 1997
Using the projection method for frames [\textit{O. Christensen}, Appl. Comput. Harmon. Anal. 1, No. 1, 50-53 (1993; Zbl 0849.42025)] this paper gives two equivalent conditions for a frame to be a Riesz basis in a separable Hilbert space. These conditions emerge from taking the limit in a sequence of nested finite dimensional subspaces.
Kim, Hong Oh, Lim, Jae Kun
openaire   +3 more sources

WEIGHTED RIESZ BASES IN G-FUSION FRAMES AND THEIR PERTURBATION [PDF]

Проблемы анализа, 2020
In this paper, we introduce orthonormal and Riesz bases for g-fusion frames and show that the weights have basic roles. Next, we prove an effective theorem between frames and g-fusion frames by using an operator. Finally, perturbations of g-fusion frames
Gh. Rahimlou, V. Sadri, R. Ahmadi
doaj   +2 more sources

Wireless Multicarrier Communications via Multipulse Gabor Riesz Bases [PDF]

EURASIP Journal on Advances in Signal Processing, 2006
We introduce multipulse multicarrier (MPMC) modulation, a wireless communication scheme that augments traditional single-pulse multicarrier systems by using multiple pulses at the transmitter and the receiver. The mathematical foundation of MPMC systems
Matz Gerald, Schafhuber Dieter, Hartmann Manfred M   +2 more
doaj   +2 more sources

Riesz Bases in Krein Spaces [PDF]

Indian Journal of Pure and Applied Mathematics
We start by introducing and studying the definition of a Riesz basis in a Krein space $(\mathcal{K},[.,.])$, along with a condition under which a Riesz basis becomes a Bessel sequence. The concept of biorthogonal sequence in Krein spaces is also introduced, providing an equivalent characterization of a Riesz basis.
Jahan, Shah, Johnson, P. Sam
openaire   +3 more sources

Riesz-Like Bases in Rigged Hilbert Spaces [PDF]

Zeitschrift für Analysis und ihre Anwendungen, 2016
The notions of Bessel sequence, Riesz-Fischer sequence and Riesz basis are generalized to a rigged Hilbert space \mathcal D[t] \subset \mathcal H \subset \mathcal D^\times[t^\times] .
Bellomonte, G., Trapani, C.
openaire   +6 more sources

Unions of exponential Riesz bases [PDF]

AIMS Mathematics
<p>We have developed new methods for constructing exponential Riesz bases by combining existing ones. These methods involve taking unions of frequency sets and domains respectively, offering easier construction compared to known techniques. Along with examples illustrating our methods, we also provide several examples that highlight the intricate
Lee, Dae Gwan
openaire   +4 more sources