فهرست مطالب

Journal of Linear and Topological Algebra
Volume:8 Issue: 1, Winter 2019

  • تاریخ انتشار: 1397/11/12
  • تعداد عناوین: 7
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  • M. Naroei Irani, A. Nazari * Pages 1-10
    ‎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 are studied‎. ‎Also‎, ‎we show that there exist two differences between $ ast $-frames in Hilbert pro-$ C^* $-modules and Hilbert $ C^* $-modules‎. ‎Finally‎, ‎dual $ ast $-frames in Hilbert pro-$ C^* $-modules are presented‎.
    Keywords: Hilbert modules over pro-C*-algebras‎, ‎standard frame of multipliers‎, ‎standard *-frame of multipliers‎, *-frame operator‎, ‎pre-*-frame operator
  • A. Jahanbani * Pages 11-24
    ‎Let $G$ be a graph of order $n$ with vertices labeled as $v_1‎, ‎v_2,dots‎ , ‎v_n$‎. ‎Let $d_i$ be the degree of the vertex $v_i$ for $i = 1‎, ‎2‎, ‎cdots‎ , ‎n$‎. ‎The Albertson matrix of $G$ is the square matrix of order $n$ whose $(i‎, ‎j)$-entry is equal to $|d_i‎ - ‎d_j|$ if $v_i $ is adjacent to $v_j$ and zero‎, ‎otherwise‎. ‎The main purposes of this paper is to introduce the Albertson energy and Albertson-Estrada index of a graph‎, ‎both base on the eigenvalues of the Albertson matrix‎. ‎Moreover‎, ‎we establish upper and lower bounds for these new graph invariants and relations between them‎‎.
    Keywords: Eigenvalue of graph, energy, Albertson Estrada index, Albertson energy
  • M. Ozkoc *, K. Sarıkaya Atasever Pages 25-39
    ‎The main goal of this paper is to introduce and study two new class of functions‎, ‎called weakly $e^*$-irresolute functions and strongly $e^*$-irresolute functions‎, ‎via the notion of $e^*$-open set defined by Ekici [7]. ‎We obtain several fundamental properties and characterizations of these functions‎. ‎Moreover‎, ‎we investigate not only some of their basic properties but also their relationships with other types of already existing topological functions‎.
    Keywords: $e^*$-open, $e^*$-$theta$-open, weakly $e^*$-irresolute, strongly $e^*$-irresolute, strongly $e^*$-regular space
  • H. Majani * Pages 41-52
    ‎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 coming‎ ‎from quantum physics‎, ‎p--adic strings and superstrings‎. ‎In this paper‎, ‎we prove‎ ‎the generalized Hyers--Ulam--Rassias stability for a‎ ‎system of additive‎, ‎quadratic and cubic functional equations in‎ ‎non--Archimedean normed spaces‎.
    Keywords: Additive‎, ‎quadratic‎, ‎cubic‎, ‎functional equation‎, ‎non--Archimedean spaces‎, ‎generalized Hyers--Ulam--Rassias stability
  • M. Sanaei, Sh. Sahebi *, H. H. S. Javadi Pages 53-61
    In this paper, some properties of $alpha$-skew Armendariz and central Armendariz rings have been studied by variety of others. We generalize the notions to central $alpha$-skew Armendariz rings and investigate their properties. Also, we show that if $alpha(e)=e$ for each idempotent $e^{2}=e in R$ and $R$ is $alpha$-skew Armendariz, then $R$ is abelian. Moreover, if $R$ is central $alpha$-skew Armendariz, then $R$ is right p.p-ring if and only if $R[x;alpha]$ is right p.p-ring. Then it is proved that if $alpha^{t}=I_{R}$ for some positive integer $t$, $ R $ is central $ alpha $-skew Armendariz if and only if the polynomial ring $ R[x] $ is central $ alpha $-skew Armendariz if and only if the Laurent polynomial ring $R[x,x^{-1}]$ is central $alpha$-skew Armendariz.‎
    Keywords: $alpha$-skew Armendariz rings, central Armendariz rings, central $alpha$-skew Armendariz rings
  • S. Sharma *, M. Ram Pages 63-70
    We introduce and study a new class of spaces, namely $beta-$topological vector spaces via $beta-$open sets. The relationships among these spaces with some existing spaces are investigated. In addition, some important and useful characterizations of $beta-$topological vector spaces are provided.
    Keywords: $beta-$open sets, $beta-$closed sets, $beta-$topological vector spaces
  • M. Elomari *, S. Melliani, A. Taqbibt, S. Chadli Pages 71-84
    ‎The present paper is devoted to the existence and uniqueness result of the fractional evolution equation $D^{q}_c u(t)=g(t,u(t))=Au(t)+f(t)$‎ ‎for the real $qin (0,1)$ with the initial value $u(0)=u_{0}intilde{R}$‎, ‎where $tilde{R}$ is the set of all generalized real numbers and $A$ is an operator defined from $mathcal G$ into itself‎. Here the Caputo fractional derivative $D^{q}_c$ is used instead of the usual derivative. The introduction of locally convex spaces is to use their topology in order to define generalized semigroups and generalized fixed points, then to show our requested result.
    Keywords: Colombeau algebra, locally convexe space, generalized semigroup, generalized fixed point