Two Bessel sequences are orthogonal if the composition of the synthesis operator of one sequence with the analysis operator of the other sequence is the 0 operator. We characterize when two Bessel sequences are orthogonal when the Bessel sequences have the form of translates of a finite number of functions in L(R). The characterizations are applied to Bessel sequences which have an affine struc...

This paper introduces the concept of Bessel multipliers. These operators are defined by a fixed multiplication pattern, which is inserted between the analysis and synthesis operators. The proposed concept unifies the approach used for Gabor multipliers for arbitrary analysis/synthesis systems, which form Bessel sequences, like wavelet or irregular Gabor frames. The basic properties of this clas...

Recently D.T. Stoeva proved that if two Bessel sequences in a separable Hilbert space $\mathcal H$ are biorthogonal and one of them is complete H$, then both Riesz bases for H$. This improves well known result where completeness assumed on sequences.
 In this note we present an alternative proof Stoeva's which quite short elementary, based the notion Riesz-Fischer sequences.

g-frames in hilbert spaces are a redundant set of operators which yield a repre-sentation for each vector in the space. in this paper we investigate the connection betweeng-frames, g-orthonormal bases and g-riesz bases. we show that a family of bounded opera-tors is a g-bessel sequences if and only if the gram matrix associated to its denes a boundedoperator.

Discrete analogs of the index transforms, involving Bessel and Lommel functions are introduced investigated. The corresponding inversion theorems for suitable classes sequences established.

Abstract Discrete analogues of the index transforms, involving Bessel and modified functions, are introduced investigated. The corresponding inversion theorems for suitable classes functions sequences established.

In this paper we study the Feichtinger Conjecture in frame theory, which was recently shown to be equivalent to the 1959 Kadison-Singer Problem in C-Algebras. We will show that every bounded Bessel sequence can be decomposed into two subsets each of which is an arbitrarily small perturbation of a sequence with a finite orthogonal decomposition. This construction is then used to answer two open ...

Discrete analogues of the index transforms with squares Bessel functions first and second kind Jν(z),Yν(z) are introduced investigated. The corresponding inversion theorems for suitable classes sequences established.