On a New G-Frame and Duality
Pages 1-9
https://doi.org/10.22072/wala.2017.51870.1089
Reihaneh Raisi Tousi, Rajab Ali Kamyabi Gol, Hosein Avazzadeh
Abstract We introduce a new g-frame (singleton g-frame), g-orthonormal basis and g-Riesz basis and study corresponding notions in some other generalizations of frames.
Also, we investigate duality for some kinds of g-frames. Finally, we illustrate an example which provides a suitable translation from discrete frames to Sun's g-frames.
A Necessary Condition for a Shearlet System to be a Frame via Admissibility
Pages 11-26
https://doi.org/10.22072/wala.2017.59948.1105
Mojgan Aminkhah, Ataollah Askari Hemmat, Reihaneh Raisi Tousi
Abstract Necessary conditions for shearlet and cone-adapted shearlet systems to be frames are presented with respect to the admissibility condition of generators.
Banach Pair Frames
Pages 27-47
https://doi.org/10.22072/wala.2017.60236.1107
Abolhassan Fereydooni, Ahmad Safapour
Abstract In this article, we consider pair frames in Banach spaces and introduce Banach pair frames. Some various concepts in the frame theory such as frames, Schauder frames, Banach frames and atomic decompositions are considered as special kinds of (Banach) pair frames. Some frame-like inequalities for (Banach) pair frames are presented. The elements that participant in the construction of (Banach) pair frames are characterized. It is shown that a Banach space $\mathrm{X}$ has a Banach pair frame with respect to a Banach scalar sequence space $\ell$, when it is precisely isomorphic to a complemented subspace of $\ell$.
It is shown that if we are allowed to choose the scalar sequence space, pair frames and Banach pair frames with respect to the chosen scalar sequence space denote the same concept.
Some Results on Convex Spectral Functions: I
Pages 49-56
https://doi.org/10.22072/wala.2017.66630.1123
Ali Reza Sattarzadeh, Hossein Mohebi
Abstract In this paper, we give a fundamental convexity preserving for spectral functions. Indeed, we investigate infimal convolution, Moreau envelope and proximal average for convex spectral functions, and show that this properties are inherited from the properties of its corresponding convex function. This results have many applications in Applied Mathematics such as semi-definite programmings and engineering problems.
p-adic Shearlets
Pages 57-71
https://doi.org/10.22072/wala.2017.61717.1112
Mahdieh Fatemidokht, Ataollah Askari Hemmat
Abstract The field $Q_{p}$ of $p$-adic numbers is defined as the completion of the field of the rational numbers $Q$ with respect to the $p$-adic norm $|.|_{p}$. In this paper, we study the continuous and discrete $p-$adic shearlet systems on $L^{2}(Q_{p}^{2})$. We also suggest discrete $p-$adic shearlet frames. Several examples are provided.
The Sign-Real Spectral Radius for Real Tensors
Pages 73-87
https://doi.org/10.22072/wala.2018.71992.1134
Hamid Reza Afshin, Ali Reza Shojaeifard
Abstract In this paper a new quantity for real tensors, the sign-real spectral radius, is defined and investigated. Various characterizations, bounds and some properties are derived. In certain aspects our quantity shows similar behavior to the spectral radius of a nonnegative tensor. In fact, we generalize the Perron Frobenius theorem for nonnegative tensors to the class of real tensors.