Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Inclusions and coincidences for multiple Cohen positive strongly $p$−summing $m$−linear operators16217418268910.22034/kjm.2023.378766.2736ENHalimaHamdiLaboratory of Pure and Applied Mathematics, University of Amar Telidji. Laghouat, AlgeriaAmarBelacelLaboratory of Pure and Applied Mathematics, University of Amar Telidji. Laghouat, AlgeriaAmarBougoutaiaDepartment of Mathematics, University of Laghouat, AlgeriaJournal Article20221229In this paper we compare the new class of multiple Cohen positive strongly $p$-summing multilinear operators along with different classes of positive multilinear summability including the classes of Cohen positive strongly summing $m$-linear operators and positive multiple summing $m$-linear operators. Moreover, we investigate a duality relationship in terms of tensor norm.https://www.kjm-math.org/article_182689_94e06ac322869689ed27c5b30487c82f.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701A note on an algorithm for solution of the Lyapunov matrix equation17518518269210.22034/kjm.2023.341952.2542ENMustaphaRaissouliDepartment of Mathematics, University of Moulay Ismail, Meknes, MoroccoNawalAl-harbiDepartment of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi ArabiaDaoudMashatDepartment of Mathematics, College of Sciences, King Khalid University, Abha 61413, Saudi ArabiaJournal Article20220511In this paper, a matrix iterative algorithm is resorted to in the aim to solve numerically the well-known Lyapunov matrix equation $AX+XA^T=C$ that arises in some areas of applied science. Some numerical examples illustrating the significance of our approach and showing the interest of this work are provided as well.https://www.kjm-math.org/article_182692_f06ebdb6ed3b11d17ac8fbd0064acce1.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Selection games with minimal usco maps18620918271310.22034/kjm.2023.349347.2579ENChristopherCaruvanaSchool of Sciences, Faculty, Indiana University Kokomo, Kokomo, IN, United States of AmericaJournal Article20220628We establish relationships between various topological selection games involving the space of minimal usco maps with various topologies, including the topology of pointwise convergence and the topology of uniform convergence on compact sets, and the underlying domain using full- and limited-information strategies. We also tie these relationships to analogous results related to spaces of continuous functions. The primary games we consider include Rothberger-like games, generalized point-open games, strong fan-tightness games, Tkachuk's closed discrete selection game, and Gruenhage's \(W\)-games.https://www.kjm-math.org/article_182713_f0a11372a7116dbb9289a3f85b493d8a.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701General energy decay for a viscoelastic wave equation with space-time damping coefficient in $\mathbb{R}^n$21022418271410.22034/kjm.2023.350018.2587ENPaul AdewaleOgbiyeleDepartment of Mathematics, University of Ibadan, Ibadan, NigeriaSalim AMessaoudiDepartment of Mathematical Sciences, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi ArabiaJournal Article20220703In this paper, we consider the following viscoelastic wave equation <br />\begin{equation}\small\nonumber<br />\left\{<br />\begin{split}<br />&u_{tt} -\bigl(\Delta u-\int^t_0 g(t-s)\Delta u(s) ds\bigr) + b(t , x) u_t +|u|^{p-1} u =0,\quad t >0, \; x\in \mathbb{R}^n\\<br />&u(0 , x ) = u_0(x), \qquad u_t(0 , x) = u_1(x), \qquad x\in \mathbb{R}^n,<br />\end{split}<br />\right.<br />\end{equation}<br />with space-time dependent potential and where the initial data $u_0(x)$, $u_1(x)$ have compact supports. Under suitable assumptions on the potential $b$ and for a relaxation function $g$ satisfying the condition $g^{\prime}(t) \leq -\mu(t) g^r(t),\quad t\geq 0,\; 1< r<\frac{3}{2}$, we obtain a general energy decay result that extends other results in the literature.https://www.kjm-math.org/article_182714_15c8a3d177b78804c8972e5af795f5c8.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701On better approximation order for the nonlinear Bleimann-Butzer-Hahn operator of maximum product kind22524518272010.22034/kjm.2023.357068.2641ENSezinCitDepartment of Mathematics, Faculty of Science, Gazi University, Turkey0000-0002-2668-3730OgunDoğruDepartment of Mathematics, Faculty of Science, Gazi University, Turkey0000-0002-2301-9957Journal Article20220820Using maximum instead of sum, nonlinear Bleimann-Butzer-Hahn operator of maximum product kind was introduced. The present paper deals with the approximation processes for this operator. In a previous study, it was indicated that the order of approximation of this operator to the function f under the modulus is $((x+1)^{(3/2)}√x)/(√n)$ and it could not be improved except for some subclasses of functions. Contrary to this claim, under some special conditions, we will show that a better order of approximation can be obtained with the help of classical and weighted modulus of continuities.https://www.kjm-math.org/article_182720_3c80a39e7c0882c76b04ff7e1dad977a.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Lie ideals and generalized derivations in prime rings and Banach algebras24625518272310.22034/kjm.2023.354981.2624ENKarimBouchannafaDepartment of Mathematics, Faculty of Sciences and Technology, Sidi Mohamed ben Abdellah University, Fez, MoroccoAbderrahmaneHermasDepartment of Mathematics, Faculty of Sciences and Technology, Sidi Mohamed ben Abdellah University, Fez, MoroccoLahcenOukhtiteDepartment of Mathematics, Faculty of Sciences and Technology, Sidi Mohamed ben Abdellah University, Fez, MoroccoJournal Article20220805Let $R$ be a prime ring and $L$ a non-central Lie ideal of $R$. The main purpose of this paper is to describe generalized derivations of $R$ satisfying some algebraic identities on $L$. Moreover, using a topological approach based on Baire’s category theorem and some properties of functional analysis, our results have been extended to Banach algebras.https://www.kjm-math.org/article_182723_e96ffa80ac60c054784848f06b899254.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701On the Betti numbers of monomial ideals and their powers25626218272410.22034/kjm.2023.378145.2733ENRezaAbdolmalekiSchool of Mathematics, Institute for Research in Fundamental Sciences (IPM), P.O. Box: 19395-5746, Tehran, Iran\\
jkh0000-0002-5608-3971RashidZaareNahandiDepartment of Mathematics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, IranJournal Article20221225Let $S=\mathbb K[x_1,\ldots,x_n]$ the polynomial ring over a field $\mathbb K$. In this paper for some families of monomial ideals $I \subset S$ we study the minimal number of generators of $I^k$. We use this results to find some other Betti numbers of these families of ideals for special choices of $n$, the number of variables.https://www.kjm-math.org/article_182724_8c7400fa347a2ead61caa9345b452a5f.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Boundedness of the Hardy-Littlewood maximal operator, fractional integral operators, and Calder\'on-Zygmund operators on generalized weighted Morrey spaces26328718272510.22034/kjm.2023.386608.2779ENYusufRamadanaFaculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Bandung 40132, Indonesia0009-0008-1762-7850HendraGunawanFaculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Bandung 40132, Indonesia0000-0001-7879-8321Journal Article20230220In this paper we investigate the boundedness of three classical operators, namely the Hardy-Littlewood maximal operator, fractional integral operators, and Calder\'{o}n-Zygmund operators, on generalized weighted Morrey spaces and generalized weighted weak Morrey spaces. We prove that each of the three operators is bounded on these function spaces under some assumptions.https://www.kjm-math.org/article_182725_7a043e6093c6797ff36b9260c85ae835.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Applications of nonhomogenous Cauchy-Euler fractional $q$-differential equation to a new class of analytic functions28829918272610.22034/kjm.2023.390830.2818ENSerapBulutKocaeli University, Faculty of Aviation and Space
Sciences, Arslanbey Campus, 41285 Kartepe-Kocaeli, Turkey0000-0002-6506-4588Journal Article20230324In this paper, we define a new general fractional $q$-differential operator and by means of this operator we introduce a new subclass of analytic functions which are the solutions of the nonhomogenous Cauchy-Euler fractional $q$-differential equations. Our aim is to determine upper bounds of Taylor-Maclaurin coefficients for functions belong to this class.https://www.kjm-math.org/article_182726_7919462af5c919f63f216fa42ca327fa.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Subordination problems for certain meromorphic functions30031318272710.22034/kjm.2023.393104.2841ENH. ÖzlemGüneyDepartment of Mathematics, Faculty of Science, Dicle University, Diyarbakır, TurkeyShigeyoshiOwaHonorary Professor, ``1 Decembrie 1918"
University of Alba Iulia, 510009 Alba Iulia, RomaniaJournal Article20230414Let $\Sigma$ be the class of meromorphic functions $f(z)$ of the form $f(z)=\frac{1}{z}+a_0+a_1z+\cdots$ which are analytic in the punctured disk $\mathbb{U}_0.$ For $f(z)\in\Sigma,$ operators $D^n f(z)$ with $n\in \mathbb{Z}=\{\cdots,-1,0,1,\cdots\}$ are introduced. Applying differential subordinations for analytic functions in the open unit disc $\mathbb{U},$ some interesting properties of $f(z)\in\Sigma$ with $D^n f(z)$ are discussed and argument problems of $D^n f(z)$ are given. Also, we consider some simple problems for our results.https://www.kjm-math.org/article_182727_226dbdeb1c0a993135cea0d6784d8f7c.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Conformally closed weakly Berwald metrics31432118272810.22034/kjm.2023.389192.2801ENAkbarTayebiDepartment of Mathematics, Faculty of Science, University of Qom, Qom, Iran0000-0002-6380-7624FaezehEslamiDepartment of Mathematics, Faculty of Science, University of Qom, Qom, IranJournal Article20230310A weakly Berwald metric is called a conformally closed weakly Berwald metric if for any conformal change remains a weakly Berwald metric. In this paper, we study the conformally closed weakly Berwald metrics and find the necessary and sufficient condition under which a weakly Berwald metric be conformally closed. We show that a Randers metric is a conformally closed weakly Berwald metric if and only if it is a Riemannian metric or the conformal transformation is homothety.https://www.kjm-math.org/article_182728_3be59027187c878421485f7477315ef0.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47889220230701Some cohomological properties of generalized module extension Banach algebras32233118272910.22034/kjm.2023.384984.2767ENMahdiehAlikahiSchool of Mathematics and Computer Science,
Damghan University, P. O. Box 36716, Damghan 41167, IranMohammadRamezanpourSchool of Mathematics and Computer Science,
Damghan University, P. O. Box 36716, Damghan 41167, Iran0000-0002-7756-7772Journal Article20230207Let $A$ and $X$ be Banach algebras such that $X$ is a Banach algebraic $A$-module. The generalized module extension $A\bowtie X$, which is a strongly splitting Banach algebra extension of $X$ by $A$, was recently introduced and studied. Many known Banach algebras such as module extension, Lau product, (generalized) semidirect product and also the direct product of Banach algebras have this general framework. We first investigate the $n$-weak amenability of $A\bowtie X$ and then we characterize its cyclic amenability improving some known results. We also examine our results to some special generalized module extension algebras. Furthermore, we characterize the cyclic amenability of some concrete Banach algebras related to locally compact groups.https://www.kjm-math.org/article_182729_64fdad5617902ed557553a3562b758bc.pdf