@article {
author = {Alimohammadi, Davood and Daneshmand, Safoura},
title = {Generalized peripherally multiplicative maps between real Lipschitz algebras with involution},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {1-31},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.200073.1555},
abstract = {Let $(X,d)$ 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 f\in Lip(X,d):f\circ\tau=\bar{f}\rbrace $. For each $f\in \mathcal{A}$, $\sigma_{\pi,\mathcal{A}}(f)$ 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 $f,g\in \mathcal{A}$, 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 $\tau \circ\varphi=\varphi \circ \eta$ on $Y$ such that $T_{j}(f)=\kappa_{j}\cdot(S_{j}(f)\circ\varphi)$ for all $f\in \mathcal{A}$ 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 $\sigma_{\pi,\mathcal{B}}(T_{1}(f)T_{2}(g))\cap\sigma_{\pi,\mathcal{A}}(S_{1}(f)S_{2}(g))\neq\emptyset$ for all $f,g\in \mathcal{A}$.},
keywords = {Peripheral spectrum,norm multiplicative,peaking function,$(i)$-peaking function,weighted composition operator},
url = {http://www.kjm-math.org/article_123046.html},
eprint = {http://www.kjm-math.org/article_123046_39ebcb541a05a639e530b9a5a3a5fc0e.pdf}
}
@article {
author = {Mirhosseinkhani, Ghasem and Akbarpour, Mahboobeh},
title = {A cartesian closed subcategory of topological molecular lattices},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {32-39},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.117858.1095},
abstract = {A 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.},
keywords = {Topological molecular lattices,Exponentiable object,Cartesian closed category},
url = {http://www.kjm-math.org/article_123047.html},
eprint = {http://www.kjm-math.org/article_123047_ba83a4356cfaf58601dadafd004634b7.pdf}
}
@article {
author = {Kocinac, Ljubisa and Lakehal, Rachid and Seba, Djamila},
title = {Almost and weakly NSR, NSM and NSH spaces},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {40-51},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.224608.1753},
abstract = {In this paper we introduce and study some new types of star-selection principles (almost and weakly neighbourhood star-Menger, neighbourhood star-Rothberger and neighbourhood star-Hurewicz). We establish some properties of these selection principles and their relations with other selection properties of topological spaces. Behaviour of these classes of spaces under certain kinds of mappings is also considered.},
keywords = {Selection principles,star-Menger,star-Rothberger,almost NSM,weakly NSM},
url = {http://www.kjm-math.org/article_123048.html},
eprint = {http://www.kjm-math.org/article_123048_64af716d7e2165b79e543fdc6760fe3a.pdf}
}
@article {
author = {Palli, Murali Mohan Kumar and Ravi Kanth, A.S.V.},
title = {Numerical simulation for a class of singularly perturbed convection delay problems},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {52-64},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.210616.1650},
abstract = {This 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.},
keywords = {Parametric cubic spline,Singular perturbation,Oscillatory},
url = {http://www.kjm-math.org/article_123049.html},
eprint = {http://www.kjm-math.org/article_123049_f09f8c2bf11cfffa3f1889fb0187a397.pdf}
}
@article {
author = {Bhardwaj, Manoj and Tyagi, Brij Kishore and Singh, Sumit},
title = {On $S\mathcal{I}H$-property and $SS\mathcal{I}H$-property in topological spaces},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {65-76},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.209741.1637},
abstract = {In 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.},
keywords = {Hurewicz space,Stone-$acute{C}$ech compactification,strongly star-$mathcal{I}$-Hurewicz,star-$mathcal{I}$-Hurewicz property},
url = {http://www.kjm-math.org/article_123050.html},
eprint = {http://www.kjm-math.org/article_123050_260ec1358e9cecfff939e2bfde28a389.pdf}
}
@article {
author = {Rezaei, Gholam Reza and Asadzadeh, Mohammad Sina and Jamalzadeh, Javad},
title = {Topological characterization of chainable sets and chainability via continuous functions},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {77-85},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.219320.1710},
abstract = {In 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 their definition appropriately and consequently, we give appropriate results and counterexamples.},
keywords = {ϵ-chainable,function-f-chainable,ultrapseudocompact},
url = {http://www.kjm-math.org/article_123052.html},
eprint = {http://www.kjm-math.org/article_123052_e4c5804fe16f5bd6826091dbe093035d.pdf}
}
@article {
author = {Azroul, Elhoussine and Balaadich, Farah},
title = {A note on quasilinear parabolic systems in generalized spaces},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {86-95},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.211591.1660},
abstract = {We study the existence of solutions for quasilinear parabolic systems of the form \[\partial_tu-\text{div}\,\sigma(x,t,Du)=f\quad\text{in}\;Q=\Omega\times(0,T),\] whose right hand side belongs to $W^{-1,x}L_{\overline{M}}(Q;\R^m)$, supplemented with the conditions $u=0$ on $\partial\Omega\times(0,T)$ 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.},
keywords = {Quasilinear parabolic systems,Orlicz-Sobolev spaces,Young measures},
url = {http://www.kjm-math.org/article_123053.html},
eprint = {http://www.kjm-math.org/article_123053_c7a14ce25359e34125f6f9f0a926b6b2.pdf}
}
@article {
author = {Alomari, Mohammad},
title = {Some numerical radius inequalities for the \v{C}eby\v{s}ev functional and non-commutative Hilbert space operators},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {96-108},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.205545.1598},
abstract = {In this work, a Gruss inequality for positive Hilbert space operators is proved. So, some numerical radius inequalities are proved. On the other hand, based on a non-commutative Binomial formula, a non-commutative upper bound for the numerical radius of the summand of two bounded linear Hilbert space operators is proved. A commutative version is also obtained as well.},
keywords = {Cebysev functional,Numerical radius,non-commutative operators},
url = {http://www.kjm-math.org/article_123054.html},
eprint = {http://www.kjm-math.org/article_123054_95180e8fafd8455d3b205a32b33c39df.pdf}
}
@article {
author = {Hosseinzadeh, Roja},
title = {Maps strongly preserving the square zero of $ \lambda $-Lie product of operators},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {109-114},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.210055.1640},
abstract = {Let $\mathcal{A}$ be a standard operator algebra on a Banach space $\mathcal{X}$ with $\dim \mathcal{X}\geq 2$. In this paper, we characterize the forms of additive maps on $\mathcal{A}$ which strongly preserve the square zero of $ \lambda $-Lie product of operators, i.e., if $\phi:\mathcal{A}\longrightarrow \mathcal{A}$ is an additive map which satisfies $$ [A,B]^2_{\lambda}=0 \Rightarrow [\phi(A),B]^2_{\lambda}=0,$$ for every $A,B \in \mathcal{A}$ and for a scalar number $\lambda$ with $\lambda \neq -1$, then it is shown that there exists a function $\sigma: \mathcal{A} \rightarrow \mathbb{C}$ such that $\phi(A)= \sigma(A) A$, for every $A \in \mathcal{A}$.},
keywords = {Preserver problem,Standard operator algebra,$ lambda $-Lie product,Lie product},
url = {http://www.kjm-math.org/article_123055.html},
eprint = {http://www.kjm-math.org/article_123055_e133eab51da403a9932eca15e4692c88.pdf}
}
@article {
author = {Zamani Bahabadi, Ali Reza and Effati, Mona and Honary, Bahman},
title = {Some remarks on chaos in nonautonomous dynamical systems},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {115-130},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.209183.1631},
abstract = {We 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. 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. 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.},
keywords = {Nonautonomous dynamical systems,Transitivity,Sen- sitivity,chaos},
url = {http://www.kjm-math.org/article_123056.html},
eprint = {http://www.kjm-math.org/article_123056_08214b4428e55ce385d320df099089aa.pdf}
}
@article {
author = {Sow, Thierno},
title = {Algorithm for computing a common solution of equilibrium and fixed point problems with set-valued demicontractive operators},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {131-139},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.208829.1623},
abstract = {In 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.},
keywords = {Explicit algorithm,Set-valued operators,Equilibrium problems,Fixed points problems},
url = {http://www.kjm-math.org/article_123057.html},
eprint = {http://www.kjm-math.org/article_123057_4862cd9ff26a4cf82d42841c7c89291d.pdf}
}
@article {
author = {Bourahma, Mohamed and Benkirane, Abdelmoujib and Bennouna, Jaouad},
title = {Existence of renormalized solutions for a class of nonlinear parabolic equations with generalized growth in Orlicz spaces},
journal = {Khayyam Journal of Mathematics},
volume = {7},
number = {1},
pages = {140-164},
year = {2021},
publisher = {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)},
issn = {2423-4788},
eissn = {2423-4788},
doi = {10.22034/kjm.2020.184027.1422},
abstract = {In this study, we prove an existence result of renormalized solutions for nonlinear parabolic equations of the type $$ \displaystyle\frac{\partial b(x,u)}{\partial t} -\mbox{div}\>a(x,t,u,\nabla u)-\mbox{div}\> \Phi(x,t,u)= f \quad\mbox{in }{Q_T=\Omega\times (0,T)}, $$ where $b(x,\cdot)$ is a strictly increasing $C^1$-function for every $x\in\Omega$ 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 on its conjugate $\overline{M}$.},
keywords = {Parabolic problem,Orlicz spaces,Renormalized solutions,Generalized growth},
url = {http://www.kjm-math.org/article_123058.html},
eprint = {http://www.kjm-math.org/article_123058_ec70c31a8cafddd00c989b31bea2f469.pdf}
}