Khayyam Journal of Mathematics (KJM)Khayyam Journal of Mathematics (KJM)
http://iranjournals.nlai.ir/2168/
Thu, 20 Feb 2020 12:25:42 +0100FeedCreatorKhayyam Journal of Mathematics (KJM)
http://iranjournals.nlai.ir/2168/
Feed provided by Khayyam Journal of Mathematics (KJM). Click to visit.On a New Class of Bernstein Type Operators Based on Beta Function
http://iranjournals.nlai.ir/2168/article_626110_84799.html
We develop Bernstein type operators using the Beta function and study their approximation properties. By using Korovkin's theorem, we achieve the uniform convergence of sequences of these operators. We obtain the rate of convergence in terms of modulus of continuity and establish the Voronovskaja type asymptotic result for these operators. At last the graphical comparison of these newly defined operators with few of the fundamental but significant operators is discussed.Tue, 31 Dec 2019 20:30:00 +0100Invariant Submanifolds of LP-Sasakian Manifolds
http://iranjournals.nlai.ir/2168/article_626111_84799.html
The object of the present paper is to study some geometric conditions for an invariant submanifold of an LP-Sasakian manifold to be totally geodesic. Further we consider concircular curvature tensor satisfying some geometric conditions of an invariant submanifold of an LP-Sasakian manifold to be totally geodesic. In extension, we build an example of LP-Sasakian manifold to verify our main result totally geodesic.Tue, 31 Dec 2019 20:30:00 +0100Various Energies of Commuting Graphs of Finite Nonabelian Groups
http://iranjournals.nlai.ir/2168/article_626112_84799.html
The commuting graph of a finite nonabelian group $G$ is a simple undirected graph, denoted by $Gamma_G$, whose vertex set is the noncentral elements of $G$ and two distinct vertices $x$ and $y$ are adjacent if and only if $xy = yx$. In this paper, we compute energy, Laplacian energy, and signless Laplacian energy of $Gamma_G$ for various families of finite nonabelian groups and analyze their values graphically. Our computations show that the conjecture posed in [MATCH Commun. Math. Comput. Chem. 59, (2008) 343-354 ] holds for the commuting graph of some families of finite groups.Tue, 31 Dec 2019 20:30:00 +0100Some Properties of Prime and Z-Semi-Ideals in Posets
http://iranjournals.nlai.ir/2168/article_626113_84799.html
We define the notion of z-semi-ideals in a poset $P$ and we show that if a z-semi-ideal $J$ satisfies $(ast )$-property, then every minimal prime semi-ideal containing $J$ is also a z-semi-ideal of $P.$ We also show that every prime semi-ideal is a z-semi-ideal or the maximal z-semi-ideals contained in it are prime z-semi-ideals. Further, we characterize some properties of union of prime semi-ideals of $P$ provided the prime semi-ideals are contained in the unique maximal semi-ideal of $P.$Tue, 31 Dec 2019 20:30:00 +0100Strongly Quasilinear Parabolic Systems in Divergence Form with Weak Monotonicity
http://iranjournals.nlai.ir/2168/article_626114_84799.html
The existence of solutions to the strongly quasilinear parabolic system[frac{partial u}{partial t}-text{div},sigma(x,t,u,Du)+g(x,t,u,Du)=f,]is proved, where the source term $f$ is assumed to belong to $L^{p'}(0,T; W^{-1,p'}(Omega;R^m))$. Further, we prove the existence of a weak solution by means of the Young measures under mild monotonicity assumptions on $sigma$.Tue, 31 Dec 2019 20:30:00 +0100On Approximation of Functions Belonging to some Classes of Functions by $(N,p_n,q_n)(E,theta )$ ...
http://iranjournals.nlai.ir/2168/article_626115_84799.html
We obtain some new results on the approximation of functions belonging to some classes of functions by $(N,p_n,q_n)(E,theta )$ means of conjugate series of its Fourier series. These results, under conditions assumed here, are better than those obtained previously by others. In addition, several particular results are derived from our results as corollaries.Tue, 31 Dec 2019 20:30:00 +0100On Pair of Generalized Derivations in Rings
http://iranjournals.nlai.ir/2168/article_626116_84799.html
Let $R$ be an associative ring with extended centroid $C$, let $G$ and $F$ be generalized derivations of $R$ associated with nonzero derivations $delta$ and $d$, respectively, and let $m, k, n geq1$ be fixed integers. In the present paper, we study the situations: (i)$F(x)circ_{m}G(y)=(x circ_{n} y)^{k}$, (ii) $[F(x),y]_{m}+[x,d(y)]_{n}=0$ for all $y, x$ in some appropriate subset of $R$.Tue, 31 Dec 2019 20:30:00 +0100Approximating Solutions of Third-Order Nonlinear Hybrid Differential Equations via Dhage ...
http://iranjournals.nlai.ir/2168/article_626117_84799.html
We prove the existence and approximation of solutions of the initial value problems of nonlinear third-order hybrid differential equations. The main tool employed here is the Dhage iteration principle in a partially ordered normed linear space. An example is also given to illustrate the main results.Tue, 31 Dec 2019 20:30:00 +0100On the Norm of Jordan $*$-Derivations
http://iranjournals.nlai.ir/2168/article_626118_84799.html
Let $mathcal H$ be a complex Hilbert space and let $B(mathcal H)$ be the algebra of all bounded linear operators on $mathcal H$. Let $Tin B(mathcal H)$.In this paper, we determine the norm of the inner Jordan $*$-derivation $Delta_T:Xmapsto TX-X^*T$ acting on the Banach algebra $B(mathcal{H})$. More precisely, we show that $$big{|}Delta_Tbig{|}geq 2sup_{lambdain W_0(T)}|{rm Im}(lambda)|$$in which $W_0(T)$ is the maximal numerical range of operator $T$.Tue, 31 Dec 2019 20:30:00 +0100Commuting Conjugacy Class Graph of Finite CA-Groups
http://iranjournals.nlai.ir/2168/article_626119_84799.html
Let $G$ be a finite nonabelian group. The commuting conjugacy class graph $Gamma(G)$ is a simple graph with the noncentral conjugacy classes of $G$ as its vertex set and two distinct vertices $X$ and $Y$ in $Gamma(G)$ are adjacent if and only if there are $x in X$ and $y in Y$ with this property that $xy = yx$. The aim of this paper is to obtain the structure of the commuting conjugacy class graph of finite CA-groups. It is proved that this graph is a union of some complete graphs. The commuting conjugacy class graph of certain groups are also computed.Tue, 31 Dec 2019 20:30:00 +0100On Jensen's Multiplicative Inequality for Positive Convex Functions of Selfadjoint Operators in ...
http://iranjournals.nlai.ir/2168/article_626120_84799.html
We obtain some multiplicative refinements and reverses of Jensen's inequality for positive convex/concave functions of selfadjoint operators in Hilbert spaces. Natural applications for power and exponential functions are provided.Tue, 31 Dec 2019 20:30:00 +0100On Gluing of Quasi-Pseudometric Spaces
http://iranjournals.nlai.ir/2168/article_626121_84799.html
The concept of gluing a family of $T_0$-quasi-metric spaces along subsets was introduced by Otafudu. In this article, we continue the study of externally Isbell-convex and weakly externally Isbell-convex subsets of a $T_0$-quasi-metric space. We finally investigate some properties of the resulting $T_0$-quasi-metric space obtained by gluing a family of Isbell-convex $T_0$-quasi-metric spaces attachedalong isometric subspaces.Tue, 31 Dec 2019 20:30:00 +0100