فهرست مطالب

Journal of Linear and Topological Algebra
Volume:4 Issue: 1, Winter 2015

  • تاریخ انتشار: 1394/01/12
  • تعداد عناوین: 7
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  • M. Akdag, F. Erol * Pages 1-9
    In this paper, a new class of multifunctions, called generalized $alpha(mu_{X},mu_{Y})$-continuous multifunctions, has been de ned and studied. Some characterizations and several properties concerning generalized $alpha(mu_{X},mu_{Y})$-continuous multifunctions are obtained. The relationships between generalized $alpha(mu_{X},mu_{Y})$-continuous multifunctions and some known concepts are also discussed.
    Keywords: Generalized open sets, multifunction, generalized continuity
  • P. Nosratpour Pages 11-23

    In this paper we will prove that the simple group $G_2(q)$, where $2 < q equiv 1(mod3)$ is recognizable by the set of its order components, also other word we prove that if $G$ is a fi nite group with $OC(G)=OC(G_2(q))$, then $G$ is isomorphic to $G_2(q)$.

    Keywords: prime graph, order component, linear group
  • L. Gavruta *, G. Zamani Eskandani, P. Gavruta Pages 25-34

    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 recently by Cai, Wang and Xu.

    Keywords: coherence, compressed sensing, frames
  • M. Mohammadzadeh Karizaki, M. Hassani * Pages 35-42
    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, we nd explicit solution of the operator equation $TXS^*-SX^*T^*= A$.
    Keywords: Operator equation, Moore-Penrose inverse, Complemented submodule, Closed range, Hilbert C*-module
  • M. Matinfar *, A. Riahifar Pages 43-52
    In this study, a new and efficient approach is presented for numerical solution of Fredholm integro-differential equations (FIDEs) of the second kind on unbounded domain with degenerate kernel based on operational matrices with respect to generalized Laguerre polynomials(GLPs). Properties of these polynomials and operational matrices of integration, differentiation are introduced and are ultilized to reduce the (FIDEs) to the solution of a system of linear algebraic equations with unknown generalized Laguerre coefficients. In addition, two examples are given to demonstrate the validity, efficiency and applicability of the technique.
    Keywords: Fredholm integro-differential equations, unbounded domain, generalized Laguerre polynomials, Operational matrices
  • M. Rashidi Kouchi Pages 53-63

    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. In addition, we obtain sufficient and necessary condition for a dual of a g-Riesz basis to be again a g-Riesz basis. We nd a situation for a g-Riesz basis to have unique dual g-Riesz basis. Also, we show that every modular g-Riesz basis is a g-Riesz basis in Hilbert C*-module but the opposite implication is not true.

    Keywords: Modular G-Riesz basis, G-Riesz basis, dual G-Riesz basis, Hilbert C∗-module
  • R. J. Shahkoohi, A. Razani Pages 65-85

    Here, a new certain class of contractive mappings in the b-metric spaces is introduced. Some fixed point theorems are proved which generalize and modify the recent results in the literature. As an application, some results in the b-metric spaces endowed with a partial ordered are proved.

    Keywords: fixed point, b-metric