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Sahand Communications in Mathematical Analysis - Volume:18 Issue: 4, Autumn 2021

Sahand Communications in Mathematical Analysis
Volume:18 Issue: 4, Autumn 2021

  • تاریخ انتشار: 1400/10/01
  • تعداد عناوین: 8
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  • Prasenjit Ghosh *, Tapas Samanta Pages 1-18

    We study the concept of frame in tensor product of  $n$-Hilbert spaces as tensor product of  $n$-Hilbert spaces is again an  $n$-Hilbert space. We generalize some of the known results about bases to frames in this new Hilbert space. A relationship between frame and bounded linear operator in tensor product of  $n$-Hilbert spaces is studied. Finally,;the dual frame in tensor product of  $n$-Hilbert spaces is discussed.

    Keywords: Frame, Dual frame, Tensor product of Hilbert spaces, $n$-normed space, $n$-Hilbert space
  • Ilyas Boukaroura, Seddik Djabi *, Samia Khelladi Pages 19-30
    In this work, we study two uncoupled quasistatic problems for thermo viscoplastic materials. In the model of the equation of generalised thermo viscoplasticity, both the elastic and the plastic rate of deformation depend on a parameter $theta $ which may be interpreted as the absolute temperature. The boundary conditions considered here as displacement-traction conditions as well as unilateral contact conditions. We establish a variational formulation for the model and we prove the existence of a unique weak solution to the problem, reducing the isotherm problem to an ordinary differential equation in a Hilbert space.
    Keywords: Viscoplastic, Temperature, Variational inequality, Cauchy-Lipschitz method
  • Muzeyyen Sangurlu Sezen * Pages 31-44
    In this paper,  we introduce new concepts of fuzzy $(gamma,beta )$-contraction and prove some fixed point results for fuzzy $(gamma,beta )$-contractions in complete non-Archimedean fuzzy metric spaces. Later, we define a fuzzy $(gamma,beta )$-weak contraction and establish some new fixed point results for fuzzy $(gamma,beta )$-weak contractions. Also, some examples are supplied in order to support the useability of ourresults.
    Keywords: $(gamma, beta)$-Contractions, Fixed point, non-Archimedean fuzzy metric space
  • Aysegul Caksu Guler * Pages 45-57

    The aim of this paper is to define and study the concept of $mathcal{I}$-convergence in fuzzy cone normed space which is a generalization of R. Saadati and S. M. Vaezpour type fuzzy normal space. We also obtained some basic properties of $mathcal{I}$-convergence. In fuzzy cone normed space, $mathcal{I}$-limit point and $mathcal{I}$-cluster point were defined and studied.

    Keywords: Fuzzy normed space, Fuzzy cone metric space, Ideal convergence, Ideal limit point
  • Asif Khan, Hira Nasir, Syed Shirazi * Pages 59-72
    The purpose of this article is to generalize Cebysev type inequalities for double integrals involving a weight function.By using an integral transform that is a weighted Montgomery identity, we obtained a generalized form of weighted Cebysev type inequalities in $L_m,, mgeq 1$ norm of differentiable functions. Also, we give some applications of the probability density function.
    Keywords: Cebysev inequality, Weighted Cebyvsev inequality, Montgomery identity, probability density function
  • Alireza Sarakhsi, Siamak Ashrafi * Pages 73-96
    ‎In this paper‎, ‎for a singular perturbation problem consist of the Cauchy-Euler equation with local and non-local boundary conditions‎. ‎We investigate the condition of the self-adjoint and the non-self-adjoint‎, ‎also look for the formation or non-formation of boundary layers for local boundary conditions using the Frequent uniform limit method‎. ‎Also‎, ‎for the state of non-local conditions‎, ‎we convert the non-local boundary conditions into local conditions by finding the fundamental solution and then obtaining the necessary conditions with the help of the 4-step method‎. ‎Finally‎, ‎we determine the formation or non-formation of a boundary layer for non-local conditions such as local conditions‎.
    Keywords: Singular Perturbation Problem, Boundary Layer, Fundamental Solution, Necessary Conditions
  • Behzad Esmaeili, Firooz Pashaie *, Ghorbanali Haghighatdoost Pages 97-111
    In mathematical physics, the stable hypersurfaces of constant mean curvature in pseudo-Euclidian spheres have been interested by many researchers on general relativity. As an extension, the notion of index of stability has been introduced for unstable ones. The stability index (as a rate of distance from being stable) is defined in terms of the Laplace operator $Delta$ as the trace of Hessian tensor. In this paper, we study an extension of stability index(namely, 1-index) of hypersurfaces with constant scalar curvature in pseudo-Euclidian sphere $S_1^{n+1}$. 1-index is defined based on the Cheng-Yau operator $Box$ as a natural extension of $Delta$.
    Keywords: Spacelike, Newton transformation, Lorentz-Minkowski space, 1-minimal hypersurface
  • Chanchal Garodia *, Izhar Uddin Pages 113-130
    In this paper, we obtain a new modified iteration process in the setting of CAT(0) spaces involving generalized $alpha$-nonexpansive mapping. We prove strong and $Delta$ convergence results for approximating fixed point via newly defined iteration process. Further, we reconfirm our results by non trivial example and tables.
    Keywords: CAT(0) space, Fixed point, $Delta$-convergence, Generalized $alpha$-nonexpansive mapping