Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Oscillation (27)
- Fixed point (25)
- Convex function (21)
- Fixed point theorem (21)
- Stability (20)
-
- Analytic functions (19)
- Time scales (18)
- Analytic function (16)
- Bi-univalent functions (16)
- Derivation (16)
- Univalent functions (16)
- Eigenvalues (14)
- Subordination (14)
- Boundary value problem (13)
- Eigenvalue (13)
- Asymptotic behavior (12)
- Collocation method (11)
- Crossed modules (11)
- Existence (11)
- Ideal (11)
- Rank (11)
- Coefficient bounds (10)
- Fractional derivative (10)
- Green's function (10)
- Numerical semigroup (10)
- Positive solution (10)
- Positive solutions (10)
- Riemannian manifold (10)
- Riemannian submersion (10)
- Spectrum (10)
- Publication Year
Articles 2041 - 2070 of 2781
Full-Text Articles in Entire DC Network
Invariant Parametrizations And Complete Systems Of Global Invariants Of Curves In The Pseudo-Euclidean Geometry, Ömer Pekşen, Djavvat Khadjiev, İdri̇s Ören
Invariant Parametrizations And Complete Systems Of Global Invariants Of Curves In The Pseudo-Euclidean Geometry, Ömer Pekşen, Djavvat Khadjiev, İdri̇s Ören
Turkish Journal of Mathematics
Let M(n, p) be the group of all transformations of an n-dimensional pseudo-Euclidean space E^n_p of index p generated by all pseudo-orthogonal transformations and parallel translations of E^n_p. Definitions of a pseudo-Euclidean type of a curve, an invariant parametrization of a curve and an M(n, p)-equivalence of curves are introduced. All possible invariant parametrizations of a curve with a fixed pseudo-Euclidean type are described. The problem of the M(n, p)-equivalence of curves is reduced to that of paths. Global conditions of the M(n, p)-equivalence of curves are given in terms of the pseudo-Euclidean type of a curve and the system …
Small Covers Over Products Of A Polygon With A Simplex, Yanying Wang, Yanchang Chen
Small Covers Over Products Of A Polygon With A Simplex, Yanying Wang, Yanchang Chen
Turkish Journal of Mathematics
The equivariant homeomorphism class of an (orientable) small cover over a simple convex polytope P^n bijectively corresponds to the equivalence class of its (orientable) coloring under the action of automorphism group of face poset of P^n. By calculating the number of orbits of group actions we determine the number of equivariant homeomorphism classes of small covers over products of a polygon with a simplex. Moreover, we calculate the number of equivariant homeomorphism classes of all orientable small covers over the product.
Hilbert Functions And Betti Numbers Of Reverse Lexicographic Ideals In The Exterior Algebra, Marilena Crupi, Carmela Ferro'
Hilbert Functions And Betti Numbers Of Reverse Lexicographic Ideals In The Exterior Algebra, Marilena Crupi, Carmela Ferro'
Turkish Journal of Mathematics
Let K be a field, V a K-vector space with basis e_1,...,e_n and let E be the exterior algebra of V. We study the class of reverse lexicographic ideals in E. We analyze the behaviour of their Hilbert functions and Betti numbers.
L^P Regularity Of Some Weighted Bergman Projections On The Unit Disc, Yunus Ergi̇n Zeytuncu
L^P Regularity Of Some Weighted Bergman Projections On The Unit Disc, Yunus Ergi̇n Zeytuncu
Turkish Journal of Mathematics
We show that weighted Bergman projections, corresponding to weights of the form M(z)(1- z ^2)^\alpha, where \alpha > -1 and M(z) is a radially symmetric, strictly positive and at least C^2 function on \overline{D}, are L^p regular.
Superinjective Simplicial Maps Of The Complexes Of Curves On Nonorientable Surfaces, Elmas Irmak
Superinjective Simplicial Maps Of The Complexes Of Curves On Nonorientable Surfaces, Elmas Irmak
Turkish Journal of Mathematics
We prove that each superinjective simplicial map of the complex of curves of a compact, connected, nonorientable surface is induced by a homeomorphism of the surface, if (g, n) \in {(1, 0), (1, 1), (2, 0), (2, 1), (3, 0)} or g + n \geq 5, where g is the genus of the surface and n is the number of the boundary components.
On The Biharmonic Vector Fields, Mustapha Djaa, Hichem Elhendi, Seddik Ouakkas
On The Biharmonic Vector Fields, Mustapha Djaa, Hichem Elhendi, Seddik Ouakkas
Turkish Journal of Mathematics
The problem studied in this paper is related to the biharmonicity of a vector field from a Riemannian manifold (M,g) to its tangent bundle TM equipped with the Sasaki metric g^s. We show that a vector field on a compact manifold is biharmonic if and only if is harmonic. We also investigate the biharmonicity of vector field of M, as a map from (M,g) to (TM,g^s).
Generalized Berwald Metrics, Esmaeil Peyghan, Akbar Tayebi
Generalized Berwald Metrics, Esmaeil Peyghan, Akbar Tayebi
Turkish Journal of Mathematics
In this paper, we consider a class of Finsler metrics called generalized Berwald metrics which contains the class of Berwald metrics as a special case. We prove that every generalized Berwald metrics with non-zero scalar flag curvature or isotropic Berwald curvature is a Randers metric. Then we prove that on generalized Berwald metrics, the notions of generalized Landsberg and Landsberg curvatures are equivalent.
Weight And Nonlinearity Of Boolean Functions, Lavinia Corina Ciungu
Weight And Nonlinearity Of Boolean Functions, Lavinia Corina Ciungu
Turkish Journal of Mathematics
In this paper we analyze the weight and the nonlinearity of various types of Boolean functions. We give some general results related to rotation symmetric Boolean functions, and in particular, we prove partially a conjecture stated by Cusick and Stanica in [3].
Results Of Generalized Local Cohomology Modules Of A-Minimax Modules, Hero Saremi
Results Of Generalized Local Cohomology Modules Of A-Minimax Modules, Hero Saremi
Turkish Journal of Mathematics
Let R be a commutative Noetherian ring, M a finitely generated R-module, and N a minimax R-module. It is shown that if a is an ideal of R, such that cd(a)=1, where cd is the cohomological dimension of a in R, then H_a^j(M, N) and Ext_R^i(M,H_a^j(N)) are a-cominimax for all i,j. Furthermore, if t is a non-negative integer such that H_a^j(M, N) is a-minimax for all j
Essential Normality For Certain Weighted Composition Operators On The Hardy Space H^2, Mahsa Fatehi, Bahram Khani Robati
Essential Normality For Certain Weighted Composition Operators On The Hardy Space H^2, Mahsa Fatehi, Bahram Khani Robati
Turkish Journal of Mathematics
We characterize the essentially normal weighted composition operators C_{\psi,\varphi} on the Hardy space H^2, whenever \varphi is a linear-fractional transformation and \psi \in A(D). Also we investigate the essential normality problem for some other weighted composition operators on H^2.
P-Rank And P-Groups In Algebraic Groups, Adrien Deloro
P-Rank And P-Groups In Algebraic Groups, Adrien Deloro
Turkish Journal of Mathematics
A few remarks on the measures of the p-rank of a group equipped with a dimension, including the refutation of a result of Burdges and Cherlin.
Nilpotent Elements And Reduced Rings, Junchao Wei, Libin Li
Nilpotent Elements And Reduced Rings, Junchao Wei, Libin Li
Turkish Journal of Mathematics
In this paper, we show the following results: (1) R is a min-leftsemicentral ring if and only if eR(1-e)Re=0 for all e \in ME_l(R); (2) Quasi-normal rings, NI rings and weakly reversible rings are all min-leftsemicentral ring; (3) R is left MC2 ring if and only if aRe=0 implies eRa=0 for all e \in ME_l(R) and a \in R if and only if every projective simple left R-module is MUP-injective; (4) R is reduced if and only if R is n-regular and quasi-normal if and only if R is n-regular and weakly reversible; (5) R is strongly regular if and …
The Cyclicity Of The Period Annulus Of A Quadratic Reversible System With One Center Of Genus One, Linping Peng, Yannan Sun
The Cyclicity Of The Period Annulus Of A Quadratic Reversible System With One Center Of Genus One, Linping Peng, Yannan Sun
Turkish Journal of Mathematics
This paper is concerned with a quadratic reversible and non-Hamiltonian system with one center of genus one. By using the properties of related elliptic integrals and the geometry of some planar curves defined by them, we prove that the cyclicity of the period annulus of the considered system under small quadratic perturbations is two. This verifies Gautier's conjecture about the cyclicity of the related period annulus.
Geometrical Objects Associated To A Substructure, Fatma Özdemi̇r, Mircea Craşmareanu
Geometrical Objects Associated To A Substructure, Fatma Özdemi̇r, Mircea Craşmareanu
Turkish Journal of Mathematics
Several geometric objects, namely global tensor fields of (1,1)-type, linear connections and Riemannian metrics, associated to a given substructure on a splitting of tangent bundle, are studied. From the point of view of lifting to entire manifold, two types of polynomial substructures are distinguished according to the vanishing of not of the sum of the coefficients. Conditions of parallelism for the extended structure with respect to some remarkable linear connections are given in two forms, firstly in a global description and secondly using the decomposition in distributions. A generalization of both Hermitian and anti-Hermitian geometry is proposed.
Existence Theory For Positive Solutions Of P-Laplacian Multi-Point Bvps On Time Scales, You-Hui Su
Existence Theory For Positive Solutions Of P-Laplacian Multi-Point Bvps On Time Scales, You-Hui Su
Turkish Journal of Mathematics
This paper is concerned with the one-dimensional p-Laplacian multi-point boundary value problem on time scales T: (\varphi_p(u^{\Delta}))^{\nabla} + h(t)f(u) = 0, t \in [0,T]_T, subject to multi-point boundary conditions u(0) - B_0(\sum_{i=1}^{m-2}a_i u^{\Delta}(\xi_i)) = 0, u^{\Delta}(T) = 0, or u^{\Delta}(0) = 0, u(T) + B_1(\sum_{i=1}^{m-2}b_iu^{\Delta}(\xi'_i)) = 0, where \varphi_p(u) is p-Laplacian operator, i.e., \varphi_p(u = u ^{p-2}u, p>1, \xi_i,\xi'_i\in [0,T]_T, m \geq 3 and satisfy 0 \leq \xi_1 < \xi_2 < ... < \xi_{m-2} < \rho(T), \sigma(0) < \xi'_1 < \xi'_2 < ... < \xi'_{m-2} \leq T, a_i, b_i\in [0,\infty) (i=1,2,..., m-2). Some new sufficient conditions are obtained for the existence of at least one positive solution by using Krasnosel'skii's fixed-point theorem and new sufficient conditions are obtained for the existence of twin, triple or arbitrary odd positive solutions by using generalized Avery and Henderson fixed-point theorem and Avery-Peterson fixed-point theorem. Our results include and extend some known results. As applications, two examples are given to illustrate the main results and their differences. These results are new even for the special cases of continuous and discrete equations, as well as in the general time scale setting.
Approximation By Complex Potentials Generated By The Gamma Function, Sorin G. Gal
Approximation By Complex Potentials Generated By The Gamma Function, Sorin G. Gal
Turkish Journal of Mathematics
In this paper we find the exact orders of approximation of analytic functions by the complex versions of several potentials (including the Flett potential) generated by the Gamma function and by some singular integrals.
Cyclic Codes Over {Z_2+Uz_2+U^2z_2+\Ldots+U^{K-1}Z_2}, Mohammed Al Ashker, Mohammed Hamoudeh
Cyclic Codes Over {Z_2+Uz_2+U^2z_2+\Ldots+U^{K-1}Z_2}, Mohammed Al Ashker, Mohammed Hamoudeh
Turkish Journal of Mathematics
In this paper, we study the structure of cyclic codes of an arbitrary length n over the ring Z_2+uZ_2+u^2Z_2+\ldots+u^{k-1}Z_2, where u^k=0. Also we study the rank for these codes, and we find their minimal spanning sets. This study is a generalization and extension of the work in reference [1].
Domination Polynomials Of Cubic Graphs Of Order 10, Saeid Alikhani, Yee-Hock Peng
Domination Polynomials Of Cubic Graphs Of Order 10, Saeid Alikhani, Yee-Hock Peng
Turkish Journal of Mathematics
Let G be a simple graph of order n. The domination polynomial of G is the polynomial D(G,x)=\sum_{i=\gamma(G)}^n d(G,i) x^i, where d(G,i) is the number of dominating sets of G of size i, and \gamma(G) is the domination number of G. In this paper we study the domination polynomials of cubic graphs of order 10. As a consequence, we show that the Petersen graph is determined uniquely by its domination polynomial.
Existence Of Mild Solutions For Abstract Mixed Type Semilinear Evolution Equations, Hong-Bo Shi, Wan-Tong Li, Hong-Rui Sun
Existence Of Mild Solutions For Abstract Mixed Type Semilinear Evolution Equations, Hong-Bo Shi, Wan-Tong Li, Hong-Rui Sun
Turkish Journal of Mathematics
This paper is concerned with the existence of global mild solutions and positive mild solutions to initial value problem for a class of mixed type semilinear evolution equations with noncompact semigroup in Banach spaces. The main method is based on a new fixed point theorem with respect to convex-power condensing operator.
Properties Of Rd-Projective And Rd-Injective Modules, Lixin Mao
Properties Of Rd-Projective And Rd-Injective Modules, Lixin Mao
Turkish Journal of Mathematics
In this paper, we first study RD-projective and RD-injective modules using, among other things, covers and envelopes. Some new characterizations for them are obtained. Then we introduce the RD-projective and RD-injective dimensions for modules and rings. The relations between the RD-homological dimensions and other homological dimensions are also investigated.
Krull Dimension Of Types In A Class Of First-Order Theories, Domenico Zambella
Krull Dimension Of Types In A Class Of First-Order Theories, Domenico Zambella
Turkish Journal of Mathematics
We study a class of first-order theories whose complete quantifier-free types with one free variable either have a trivial positive part or are isolated by a positive quantifier-free formula---plus a few other technical requirements. The theory of vector spaces and the theory fields are examples. We prove the amalgamation property and the existence of a model-companion. We show that the model-companion is strongly minimal. We also prove that the length of any increasing sequence of prime types is bounded, so every formula has finite Krull dimension.
Some Properties Of Associate And Presimplifiable Rings, Manal Ghanem
Some Properties Of Associate And Presimplifiable Rings, Manal Ghanem
Turkish Journal of Mathematics
In this paper we study some properties of associate and presimplifiable rings. We give a characterization of the associate (resp., domainlike) pullback P of R_1 \rightarrow{R_3} \leftarrow{R_2}, where R_1 and R_2 are two presimplifiable (resp., domainlike) rings. We prove that R is presimplifiable ring if and only if the factor ring R/{nil(R)} is presimplifiable and the ideal nil(R) is presimplifiable. Then we investigate the associate and presimplifiable property of the dual rings {R[x]/\langle{x^2}\rangle} and its modules through the base ring R and its modules.
Module Classes And The Lifting Property, Muhammet Tamer Koşan
Module Classes And The Lifting Property, Muhammet Tamer Koşan
Turkish Journal of Mathematics
Let R be a ring. A collection of R-modules containing the zero module and closed under isomorphisms will be denoted by X. An R-module M is said to be X-lifting if for every X-submodule N of M there exists A \leq N such that M=A \oplus B and N \cap B is small in B [11]. In the present paper, we consider the question: Can we characterize X-lifting modules via objects of the class X?
Universal Inequalities And Bounds For Weighted Eigenvalues Of The Schrödinger Operator On The Heisenberg Group, Hejun Sun
Turkish Journal of Mathematics
For a bounded domain \Omega in the Heisenberg group H^n, we investigate the Dirichlet weighted eigenvalue problem of the Schrödinger operator - \Delta_{H^n} +V, where \Delta_{H^n} is the Kohn Laplacian and V is a nonnegative potential. We establish a Yang-type inequality for eigenvalues of this problem. It contains the sharpest result for \Delta_{H^n} in [17] of Soufi, Harrel II and Ilias. Some estimates for upper bounds of higher order eigenvalues and the gaps of any two consecutive eigenvalues are also derived. Our results are related to some previous results for the Laplacian \Delta and the Schrödinger operator -\Delta+V on a …
Hypersurfaces With Constant Mean Curvature In A Real Space Form, Shichang Shu, Sanyang Liu
Hypersurfaces With Constant Mean Curvature In A Real Space Form, Shichang Shu, Sanyang Liu
Turkish Journal of Mathematics
Let M^n be an n\(n \geq 3)-dimensional complete connected and oriented hypersurface in M^{n+1}(c)(c \geq 0) with constant mean curvature H and with two distinct principal curvatures, one of which is simple. We show that (1) if c=1 and the squared norm of the second fundamental form of M^n satisfies a rigidity condition (1.3), then M^n is isometric to the Riemannian product S^1(\sqrt{1-a^2}) \times S^{n-1}(a); (2) if c=0, H \neq 0 and the squared norm of the second fundamental form of M^n satisfies S \geq n^2H^2/(n-1), then M^n is isometric to the Riemannian product S^{n-1}(a)\times R or S^1(a) \times R^{n-1}
On Generalized Witt Algebras In One Variable, Ki Bong Nam, Jonathan Pakianathan
On Generalized Witt Algebras In One Variable, Ki Bong Nam, Jonathan Pakianathan
Turkish Journal of Mathematics
We study a class of infinite dimensional Lie algebras called generalized Witt algebras (in one variable). These include the classical Witt algebra and the centerless Virasoro algebra as important examples. We show that any such generalized Witt algebra is a semisimple, indecomposable Lie algebra which does not contain any abelian Lie subalgebras of dimension greater than one. We develop an invariant of these generalized Witt algebras called the spectrum, and use it to show that there exist infinite families of nonisomorphic, simple, generalized Witt algebras and infinite families of nonisomorphic, nonsimple, generalized Witt algebras. We develop a machinery that can …
On The Uniqueness Of Strongly Flat Covers Of Cyclic Acts, Majid Ershad, Roghaieh Khosravi
On The Uniqueness Of Strongly Flat Covers Of Cyclic Acts, Majid Ershad, Roghaieh Khosravi
Turkish Journal of Mathematics
In [1], strongly flat covers of cyclic acts are discussed and it is asked if strongly flat covers are unique. From this point of view, in this paper we give numerous classes of monoids over which strongly flat covers of cyclic acts are unique.
Weingarten Quadric Surfaces In A Euclidean 3-Space, Min Hee Kim, Dae Won Yoon
Weingarten Quadric Surfaces In A Euclidean 3-Space, Min Hee Kim, Dae Won Yoon
Turkish Journal of Mathematics
In this paper, we study quadric surfaces in a Euclidean 3-space. Furthermore, we classify quadric surfaces in a Euclidean 3-space in terms of the Gaussian curvature and the mean curvature.
Covers And Envelopes With Respect To A Semidualizing Module, Xiaoguang Yan, Xiaosheng Zhu
Covers And Envelopes With Respect To A Semidualizing Module, Xiaoguang Yan, Xiaosheng Zhu
Turkish Journal of Mathematics
Let R be a commutative ring and C be a semidualizing R-module. For a given class of R-modules Q, we define a class Q_C by M \in Q_C \Leftrightarrow Hom_R(C,M) \in Q. We prove that if Q \subseteq (R) is a Kaplansky class and closed under direct sums, then Q_C^{\bot} is special preenveloping. As corollaries, we can show that p_C^{n \bot} and f_C^{n \bot} are both special preenveloping. Finally, we show that I_C^n is covering, I_C^{n \bot} is enveloping and special preenveloping provided R is Noetherian.
Some Results On G-Frames In Hilbert Spaces, Abdolaziz Abdollahi, Elham Rahimi
Some Results On G-Frames In Hilbert Spaces, Abdolaziz Abdollahi, Elham Rahimi
Turkish Journal of Mathematics
In this paper we show that every g-frame for a Hilbert space H can be represented as a linear combination of two g-orthonormal bases if and only if it is a g-Riesz basis. We also show that every g-frame can be written as a sum of two tight g-frames with g-frame bounds one or a sum of a g-orthonormal basis and a g-Riesz basis for H. We further give necessary and sufficient conditions on g-Bessel sequences {\Lambda_i \in L (H,H_i) : i \in J} and {\Gamma_i \in L(H,H_i): i \in J} and operators L_1, L_2 on H so that {\Lambda_iL_1+\Gamma_iL_2: …