Volume 10 (2021)
Volume 09 (2020)
Volume 08 (2019)
Volume 07 (2018)
Volume 06 (2017)
Volume 05 (2016)
Volume 04 (2015)
Volume 03 (2014)
Volume 02 (2013)
Volume 01 (2012)
Main Subjects = Operator theory
Number of Articles: 20
1. Coupled fixed point results for $T$-contractions on $\mathcal{F}$-metric spaces and an application
Volume 10, Issue 01 , Winter 2021, , Pages 1-10
Abstract
The main purpose of this article is to introduce the concept of $T$-contraction type mappings in the function weighed metric spaces and to obtain some coupled fixed points theorems in this framework. Also, an example and an application of the existence of a solution of a system of nonlinear integral ... Read More2. A new implicit iteration process for approximating common fixed points of $\alpha$-demicontraction semigroup
Volume 10, Issue 01 , Winter 2021, , Pages 19-34
Abstract
It is our purpose in this paper to introduce the concept of $\alpha$-demicontractive semigroup. Also, we construct a new implicit iterative scheme for approximating the common fixed points of $\alpha$-demicontractive semigroup. We prove strong convergence of our new iterative scheme to the common fixed ... Read More3. Integral type contraction and coupled fixed point theorems in ordered G-metric spaces
Volume 09, Issue 02 , Spring 2020, , Pages 113-120
Abstract
In this paper, we apply the idea of integral type contraction and prove some coupled fixed point theorems for such contractions in ordered $G$-metric space. Also, we support the main results by an illustrative example. Read More4. $C$-class functions on common fixed point theorems for weak contraction mapping of integral type in modular spaces
Volume 08, Issue 04 , Autumn 2019, , Pages 265-285
Abstract
In this paper, we use the concept of $C$-class functions introduced by Ansari [4] to prove the existence and uniqueness of common fixed point for self-mappings in modular spaces of integral inequality. Our results extended and generalized ... Read More5. *-frames in Hilbert modules over pro-C*-algebras
Volume 08, Issue 01 , Winter 2019, , Pages 1-10
Abstract
In this paper, by using the sequence of multipliers, we introduce frames with algebraic bounds in Hilbert pro-$ C^* $-modules. We investigate the relations between frames and $ \ast $-frames. Some properties of $ \ast $-frames in Hilbert pro-$ C^* $-modules ... Read More6. System of AQC functional equations in non-Archimedean normed spaces
Volume 08, Issue 01 , Winter 2019, , Pages 41-52
Abstract
In 1897, Hensel introduced a normed space which does not have the Archimedean property. During the last three decades theory of non--Archimedean spaces has gained the interest of physicists for their research in particular in problems ... Read More7. Algebraic distance in algebraic cone metric spaces and its properties
Volume 07, Issue 04 , Autumn 2018, , Pages 273-280
Abstract
In this paper, we prove some properties of algebraic cone metric spaces and introduce the notion of algebraic distance in an algebraic cone metric space. As an application, we obtain some famous fixed point results in the framework of this algebraic distance. Read More8. Stability and hyperstability of orthogonally ring $*$-$n$-derivations and orthogonally ring $*$-$n$-homomorphisms on $C^*$-algebras
Volume 07, Issue 02 , Spring 2018, , Pages 109-119
Abstract
In this paper, we investigate the generalized Hyers-Ulam-Rassias and the Isac and Rassias-type stability of the conditional of orthogonally ring $*$-$n$-derivation and orthogonally ring $*$-$n$-homomorphism on $C^*$-algebras. As a consequence of this, we prove the hyperstability of orthogonally ring ... Read More9. Characterization of $(\delta, \varepsilon)$-double derivation on rings and algebras
Volume 06, Issue 03 , Summer 2017, , Pages 191-198
Abstract
This paper is an attempt to prove the following result:Let $n>1$ be an integer and let $\mathcal{R}$ be a $n!$-torsion-free ring with the identity element. Suppose that $d, \delta, \varepsilon$ are additive mappings satisfying\begin{equation}d(x^n) = \sum^{n}_{j=1}x^{n-j}d(x)x^{j-1}+\sum^{n-1}_{j=1}\sum^{j}_{i=1}x^{n-1-j}\Big(\delta(x)x^{j-i}\varepsilon(x)+\varepsilon(x)x^{j-i}\delta(x)\Big)x^{i-1}\quad\end{equation}for ... Read More10. Duals and approximate duals of g-frames in Hilbert spaces
Volume 04, Issue 04 , Autumn 2015, , Pages 259-265
Abstract
In this paper we get some results and applications for duals and approximate duals of g-frames in Hilbert spaces. In particular, we consider the stability of duals and approximate duals under bounded operators and we study duals and approximate duals of g-frames in the direct sum of Hilbert spaces. We ... Read More11. New characterizations of fusion bases and Riesz fusion bases in Hilbert spaces
Volume 04, Issue 02 , Spring 2015, , Pages 131-142
Abstract
In this paper we investigate a new notion of bases in Hilbert spaces and similar to fusion frame theory we introduce fusion bases theory in Hilbert spaces. We also introduce a new de nition of fusion dual sequence associated with a fusion basis and show that the operators of a fusion dual ... Read More12. On the boundedness of almost multipliers on certain Banach algebras
Volume 04, Issue 02 , Spring 2015, , Pages 143-152
Abstract
Almost multiplier is rather a new concept in the theory of almost functions. In this paper we discussion the boundedness of almost multipliers on some special Banach algebras, namely stable algebras. We also defi ne an adjoint and extension for almost multiplier. Read More13. On dual shearlet frames
Volume 04, Issue 02 , Spring 2015, , Pages 159-163
Abstract
In This paper, we give a necessary condition for function in $L^2$ with its dual to generate a dual shearlet tight frame with respect to admissibility. Read More14. Frames for compressed sensing using coherence
Volume 04, Issue 01 , Winter 2015, , Pages 25-34
Abstract
We give some new results on sparse signal recovery in the presence of noise, for weighted spaces. Traditionally, were used dictionaries that have the norm equal to 1, but, for random dictionaries this condition is rarely satis ed. Moreover, we give better estimations then the ones given ... Read More15. The solutions to some operator equations in Hilbert $C^*$-module
Volume 04, Issue 01 , Winter 2015, , Pages 35-42
Abstract
In this paper, we state some results on product of operators with closed ranges and we solve the operator equation $TXS^*-SX^*T^*= A$ in the general setting of the adjointable operators between Hilbert $C^*$-modules, when $TS = 1$. Furthermore, by using some block operator matrix techniques, ... Read More16. On duality of modular G-Riesz bases and G-Riesz bases in Hilbert C*-modules
Volume 04, Issue 01 , Winter 2015, , Pages 53-63
Abstract
In this paper, we investigate duality of modular g-Riesz bases and g-Riesz bases in Hilbert C*-modules. First we give some characterization of g-Riesz bases in Hilbert C*-modules, by using properties of operator theory. Next, we characterize the duals of a given g-Riesz basis in Hilbert C*-module. ... Read More17. Module amenability and module biprojectivity of θ-Lau product of Banach algebras
Volume 03, Issue 03 , Summer 2014, , Pages 185-196
Abstract
In this paper we study the relation between module amenability of $\theta$-Lau product $A×_\theta B$ and that of Banach algebras $A, B$. We also discuss module biprojectivity of $A×\theta B$. As a consequent we will see that for an inverse semigroup $S$, $l^1(S)×_\theta l^1(S)$ is module ... Read More18. Operator-valued bases on Hilbert spaces
Volume 02, Issue 04 , Autumn 2013, , Pages 201-218
Abstract
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 ... Read More19. On the Finsler modules over H-algebras
Volume 02, Issue 04 , Autumn 2013, , Pages 219-227
Abstract
In this paper, applying the concept of generalized A-valued norm on a right $H^*$-module and also the notion of ϕ-homomorphism of Finsler modules over $C^*$-algebras we first improve the definition of the Finsler module over $H^*$-algebra and then define ϕ-morphism of Finsler modules over $H^*$-algebras. ... Read More20. Some algebraic properties of Lambert Multipliers on $L^2$ spaces
Volume 02, Issue 04 , Autumn 2013, , Pages 255-261