Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Generalized peripherally multiplicative maps between real Lipschitz algebras with involution13112304610.22034/kjm.2020.200073.1555ENDavoodAlimohammadiDepartment of Mathematics, Faculty of Science, Arak UniversitySafouraDaneshmandDepartment of Mathematics, Faculty of Science, Arak UniversityJournal Article20190901Let $(X,d)$ and $(Y,rho)$ be compact metric spaces, $tau$ and $eta$ be Lipschitz involutions on $ X$ and $Y$, respectively, $mathcal{A}=Lip(X,d,tau)$ and $mathcal{B}=Lip(Y,rho,eta)$, where $Lip(X,d,tau)=lbrace fin Lip(X,d):fcirctau=bar{f}rbrace $. For each $fin mathcal{A}$, $sigma_{pi,mathcal{A}}(f)$ denotes the peripheral spectrum of $f$. We prove that if $S_{1},S_{2}:mathcal{A}rightarrow mathcal{A}$ and $T_{1},T_{2}:mathcal{A}rightarrow mathcal{B}$ are surjective mappings that satisfy $sigma_{pi,mathcal{B}}(T_{1}(f)T_{2}(g))=sigma_{pi,mathcal{A}}(S_{1}(f)S_{2}(g))$ for all $f,gin mathcal{A}$, then there are $kappa_{1},kappa_{2}in Lip(Y,rho,eta)$ with $kappa_{1}kappa_{2}=1_{Y}$ and a Lipschitz homeomorphism $varphi$ from $(Y,rho)$ to $(X,d)$ with $tau circvarphi=varphi circ eta$ on $Y$ such that $T_{j}(f)=kappa_{j}cdot(S_{j}(f)circvarphi)$ for all $fin mathcal{A}$ and $j=1,2$. Moreover, we show that the same result holds for surjective mappings $S_{1},S_{2}:mathcal{A}rightarrow mathcal{A}$ and $T_{1},T_{2}:mathcal{A}rightarrow mathcal{B}$ that satisfy $sigma_{pi,mathcal{B}}(T_{1}(f)T_{2}(g))capsigma_{pi,mathcal{A}}(S_{1}(f)S_{2}(g))neqemptyset$ for all $f,gin mathcal{A}$.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101A cartesian closed subcategory of topological molecular lattices323912304710.22034/kjm.2020.117858.1095ENGhasemMirhosseinkhaniDepartment of Mathematics, Sirjan University of technologyMahboobehAkbarpourDepartment of Mathematics, University of Hormozgan, Bandarabbas, IranJournal Article20190203A category C is called cartesian closed provided that it has ﬁnite products and for each C-object A the functor (A×−) : A → A has a right adjoint. It is well known that the category TML of topological molecular lattices with generalized order homomorphims in the sense of Wang is both complete and cocomplete, but it is not cartesian closed. In this paper, we introduce a cartesian closed subcategory of this category.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Almost and weakly NSR, NSM and NSH spaces405112304810.22034/kjm.2020.224608.1753ENLjubisa D.R.KocinacDepartment of Mathematics, Faculty of Sciences and Mathematics, University of Nis, Nis, Serbia0000-0002-4870-7908RachidLakehalDynamic of Engines and Vibroacoustic Laboratory,
University M'Hamed Bougara of Boumerdes, AlgeriaDjamilaSebaDynamic of Engines and Vibroacoustic Laboratory,
University M'Hamed Bougara of Boumerdes, AlgeriaJournal Article20200326In this paper we introduce and study some new types of<br /> star-selection principles (almost and weakly neighbourhood<br /> star-Menger, neighbourhood star-Rothberger and neighbourhood<br /> star-Hurewicz). We establish some properties of these selection<br /> principles and their relations with other selection properties of<br /> topological spaces. Behaviour of these classes of spaces under<br /> certain kinds of mappings is also considered.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Numerical simulation for a class of singularly perturbed convection delay problems526412304910.22034/kjm.2020.210616.1650ENMurali Mohan KumarPalliGMR Institute of Technology0000-0001-8472-9023A.S.V.Ravi KanthDepartment of Mathematics
National Institute of Technology, Kurukshetra0000-0002-5266-7945Journal Article20191205This article presents a solution for a class of singularly perturbed convection with delay problems arising in control theory. The approach of extending Taylor's series for the convection term gives to a bad approximation when the delay is not smaller order of singular perturbation parameter. To handle the delay term, we model an interesting mesh form such that the delay term lies on mesh points. The parametric cubic spline is adapted to the continuous problem on a specially designed mesh. The truncation error for the proposed method is derived. Numerical examples are experimented to examine the effect of the delay parameter on the layer structure.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101On $Smathcal{I}H$-property and $SSmathcal{I}H$-property in topological spaces657612305010.22034/kjm.2020.209741.1637ENManojBhardwajUniversity of Delhi, IndiaBrij KishoreTyagiA.R.S.D. College, University of Delhi, IndiaSumitSinghUniversity of Delhi, IndiaJournal Article20191129In this paper, we further investigated the $SS mathcal{I} H$ and $S mathcal{I} H$ properties introduced by Das et. al recently. It is shown that regular-closed $G_delta$ subspace of $SS mathcal{I} H$ (resp., $S mathcal{I} H$) is not $SS mathcal{I} H$ (resp., $S mathcal{I} H$). The preservation properties of these spaces are studied under some maps. Also $SS mathcal{I} H$ and $S mathcal{I} H$ properties are investigated in Alexandroff space.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Topological characterization of chainable sets and chainability via continuous functions778512305210.22034/kjm.2020.219320.1710ENGholam RezaRezaeiDepartment of Mathematics, University of Sistan and Baluchestan, Zahedan, IranMohammad SinaAsadzadehDepartment of Mathematics, University of Sistan and Baluchestan, Zahedan,
Iran.JavadJamalzadehDepartment of Mathematics, University of Sistan and Baluchestan, Zahedan,
Iran.Journal Article20200209In the last decade, the notions of function-f-ϵ-chainability, uniformly function-f-ϵ-chainability, function-f-ϵ-chainable sets and locally functionf-chainable sets were studied in some papers. We show that the notions of function-f-ϵ-chainability and uniformly function-f-ϵ-chainability are equivalent to the notion of non-ultrapseudocompactness in topological spaces. Also, all of these are equivalent to the condition that each pair of non-empty subsets (resp., subsets with non-empty interiors) is function-f-ϵ-chainable (resp., locally function-f-chainable). Further, we provide a criterion for connectedness with covers. In the paper "Characterization of ϵ-chainable sets in metric spaces" (Indian J. Pure Appl. Math. 33 (2002), no. 6, 933{940), the chainability of a pair of subsets in a metric space has been defined wrongly and consequently Theorem 1 and Theorem 5 are found to be wrong. We rectify<br /> their definition appropriately and consequently, we give appropriate results and counterexamples.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101A note on quasilinear parabolic systems in generalized spaces869512305310.22034/kjm.2020.211591.1660ENElhoussineAzroulDepartment of Mathematics, Faculty of Sciences, Dhar El Mahraz FEZFarahBalaadichDepartement of Mathematics, Faculty of Sciences, Dhar El Mahraz FEZJournal Article20191212We study the existence of solutions for quasilinear parabolic systems of the form<br /> [partial_tu-text{div},sigma(x,t,Du)=fquadtext{in};Q=Omegatimes(0,T),]<br /> whose right hand side belongs to $W^{-1,x}L_{overline{M}}(Q;R^m)$, supplemented with the conditions $u=0$ on $partialOmegatimes(0,T)$ and $u(x,0)=u_0(x)$ in $Omega$. By using a mild monotonicity condition for $sigma$, namely strict quasimonotone, and the theory of Young measures, we deduce the needed result.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Some numerical radius inequalities for the v{C}ebyv{s}ev functional and non-commutative Hilbert space operators9610812305410.22034/kjm.2020.205545.1598ENMohammad W.AlomariJadara University,0000-0002-6696-9119Journal Article20191017In this work, a Gruss inequality for positive Hilbert space operators is<br /> proved. So, some numerical radius inequalities are proved. On the other hand, based on<br /> a non-commutative Binomial formula, a non-commutative upper bound for the numerical<br /> radius of the summand of two bounded linear Hilbert space operators is proved. A commutative<br /> version is also obtained as well.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Maps strongly preserving the square zero of $ lambda $-Lie product of operators10911412305510.22034/kjm.2020.210055.1640ENRojaHosseinzadehDepartment of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, P. O. Box 47416-1468, Babolsar, Iran.0000-0003-2413-1892Journal Article20191201Let $mathcal{A}$ be a standard operator algebra on a Banach space $mathcal{X}$ with $dim mathcal{X}geq 2$. In this paper, we characterize<br /> the forms of additive maps on $mathcal{A}$ which strongly preserve the<br /> square zero of $ lambda $-Lie product of operators, i.e., if $phi:mathcal{A}longrightarrow mathcal{A}$ is an additive map which satisfies<br /> $$ [A,B]^2_{lambda}=0 Rightarrow [phi(A),B]^2_{lambda}=0,$$<br /> for every $A,B in mathcal{A}$ and for a scalar number $lambda$ with $lambda neq -1$, then it is shown that<br /> there exists a function $sigma: mathcal{A} rightarrow mathbb{C}$ such that $phi(A)= sigma(A) A$, for every $A in mathcal{A}$.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Some remarks on chaos in nonautonomous dynamical systems11513012305610.22034/kjm.2020.209183.1631ENAli RezaZamani BahabadiFerdowsi University of MashhadMonaEffatiPure Mathematics, Faculty of Mathematical science, Mashhad, IranBahmanHonaryFerdowsi university of MashhhadJournal Article20191124We introduce the concept of almost thick chaos and continuously almost thick transitivity for continuous maps and nonautonomous dynamical systems (NDS). We show that NDS $f_{1,infty}$ is sensitive if it is thick transitive and syndetic.<br /> Under certain conditions, we show that NDS $(X,f_{1,infty})$ generated by a sequence $(f_n)$ of continuous maps on $X$ converging uniformly to $f$ is almost thick transitive if and only if $(X,f)$ is almost thick transitive.<br /> Moreover, we prove that if $f_{1,infty}$ is continuously almost thick transitive and syndetic, then it is strongly topologically ergodic. In addition, the relationship between the large deviations theorem and almost thick chaos is studied.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Algorithm for computing a common solution of equilibrium and fixed point problems with set-valued demicontractive operators13113912305710.22034/kjm.2020.208829.1623ENThiernoSowGaston Berger universityJournal Article20191115In this paper, we introduce an iterative algorithm based on the well-known Krasnoselskii-Mann's method for finding a common element of the set of fixed points of multivalued demicontractive mapping and the set of solutions of an equilibrium problem in a real Hilbert space. Then, strong convergence of the scheme to a common element of the two sets is proved without imposing any compactness condition on the mapping or the space. We further applied our results to solve some optimization problems. Our results improve many recent results using Krasnoselskii-Mann's algorithm for solving nonlinear problems.Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures and Tusi Mathematical Research Group)Khayyam Journal of Mathematics2423-47887120210101Existence of renormalized solutions for a class of nonlinear parabolic equations with generalized growth in Orlicz spaces14016412305810.22034/kjm.2020.184027.1422ENMohamedBourahmaLaboratory of mathematical analysis and applications (LAMA),
Department of mathematics, Faculty of Sciences Dhar el Mahraz,
Sidi Mohamed Ben Abdellah University,
PB 1796 Fez-Atlas, Fez MoroccoAbdelmoujibBenkiraneLaboratory of mathematical analysis and applications (LAMA),
Department of mathematics, Faculty of Sciences Dhar el Mahraz,
Sidi Mohamed Ben Abdellah University,
PB 1796 Fez-Atlas, Fez MoroccoJaouadBennounaLaboratory of mathematical analysis and applications (LAMA),
Department of mathematics, Faculty of Sciences Dhar el Mahraz,
Sidi Mohamed Ben Abdellah University,
PB 1796 Fez-Atlas, Fez MoroccoJournal Article20190514In this study, we prove an existence result of renormalized<br /> solutions for nonlinear parabolic equations of the type<br /> $$<br /> displaystylefrac{partial b(x,u)}{partial t}<br /> -mbox{div}>a(x,t,u,nabla u)-mbox{div}><br /> Phi(x,t,u)=<br /> f quadmbox{in }{Q_T=Omegatimes (0,T)},<br /> $$<br /> where $b(x,cdot)$ is a strictly increasing $C^1$-function for every $xinOmega$ with $b(x,0)=0$, the lower order term $Phi$ satisfies a natural growth condition described by the appropriate Orlicz function $M$ and $f$ is an element of $L^1(Q_T)$. We don't assume any restriction neither on $M$ nor<br /> on its conjugate $overline{M}$.