Abstract. We discuss the structure of decoherence-free subsystems for a bosonic channel affected by collective depolarization. A single use of the channel is defined as a transmission of a pair of bosonic modes. Collective depolarization consists in a random linear U(2) transformation of the respective mode operators, which is assumed to be identical for N consecutive uses of the channel. We de...

Let X be a countable fundamental set in a Hilbert space H, and let T be the operator X x2X c(x)x: Whenever T is well-deened and bounded, X is said to be a Bessel sequence. If, in addition, ran T is closed, then X is a frame. Finally, a frame whose corresponding T is injective is a stable basis (also known as a Riesz basis). This paper considers the above three properties for subspaces H of L 2 ...

‎let $g$ be a locally compact abelian group‎. ‎the concept of a generalized multiresolution structure (gms) in $l^2(g)$ is discussed which is a generalization of gms in $l^2(mathbb{r})$‎. ‎basically a gms in $l^2(g)$ consists of an increasing sequence of closed subspaces of $l^2(g)$ and a pseudoframe of translation type at each level‎. ‎also‎, ‎the construction of affine frames for $l^2(g)$ bas...

‎Let $G$ be a locally compact abelian group‎. ‎The concept of a generalized multiresolution structure (GMS) in $L^2(G)$ is discussed which is a generalization of GMS in $L^2(mathbb{R})$‎. ‎Basically a GMS in $L^2(G)$ consists of an increasing sequence of closed subspaces of $L^2(G)$ and a pseudoframe of translation type at each level‎. ‎Also‎, ‎the construction of affine frames for $L^2(G)$ bas...

Fusion frames are generalizations of classical frames that provide a richer description of signal spaces where subspaces are used in the place of vectors as signal building blocks. The main idea of this work is to extend ideas from Compressed Sensing (CS) to a fusion frame setup. We use a sparsity model for fusion frames and then show that sparse signals under this model can be compressively sa...

We consider three-dimensional elastic frames constructed out of Euler–Bernoulli beams and describe a simple process generating joint conditions the geometric description frame. The corresponding differential operator is shown to be self-adjoint. In special case planar frames, decomposes into direct sum two operators, one coupling out-of-plane displacement angular (torsional) other in-plane with...

In the present paper we introduce and study the notion of pairwise weakly Lindelof bitopological spaces and obtain some results. Further, we also study the pairwise weakly Lindelof subspaces and subsets, and investigate some of their properties. It was proved that a pairwise weakly Lindelof property is not a hereditary property.

Many contact tasks are more easily deened in terms of constraint equations (and therefore constraint coordinates), rather than either Cartesian or joint coordinates. Deburring and grinding are examples of two such tasks. Hybrid Impedance control has been a popular force control algorithm for these tasks. This paper gives a procedure to specify orthogonal subspaces in constraint coordinates. It ...

Abstract. In this article, we study tensor product of Hilbert C∗-modules and Hilbert spaces. We show that if E is a Hilbert A-module and F is a Hilbert B-module, then tensor product of frames (orthonormal bases) for E and F produce frames (orthonormal bases) for Hilbert A⊗B-module E ⊗F , and we get more results. For Hilbert spaces H and K, we study tensor product of frames of subspaces for H an...