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Full-Text Articles in Mathematics

The Strong ``Zero-Two" Law For Positive Contractions Of Banach--Kantorovich $L_P$-Lattices, Inomjon Ganiev, Farrukh Mukhamedov, Dilmurod Bekbaev Jan 2015

The Strong ``Zero-Two" Law For Positive Contractions Of Banach--Kantorovich $L_P$-Lattices, Inomjon Ganiev, Farrukh Mukhamedov, Dilmurod Bekbaev

Turkish Journal of Mathematics

In the present paper we study dominated operators acting on Banach--Kantorovich $L_p$-lattices, constructed by a measure $m$ with values in the ring of all measurable functions. Using methods of measurable bundles of Banach--Kantorovich lattices, we prove the strong ``zero-two" law for positive contractions of Banach--Kantorovich $L_p$-lattices. \vspace{1mm}


Moduli Spaces Of Arrangements Of 11 Projective Lines With A Quintuple Point, Meirav Amram, Cheng Gong, Mina Teicher, Wan-Yuan Xu Jan 2015

Moduli Spaces Of Arrangements Of 11 Projective Lines With A Quintuple Point, Meirav Amram, Cheng Gong, Mina Teicher, Wan-Yuan Xu

Turkish Journal of Mathematics

In this paper, we try to classify moduli spaces of arrangements of 11 lines with quintuple points. We show that moduli spaces of arrangements of 11 lines with quintuple points can consist of more than 2 connected components. We also present defining equations of the arrangements whose moduli spaces are not irreducible after taking quotients by the complex conjugation by Maple and supply some "potential Zariski pairs".


On Pseudohyperbolic Space Motions, Tunahan Turhan, Nural Yüksel, Ni̇hat Ayyildiz Jan 2015

On Pseudohyperbolic Space Motions, Tunahan Turhan, Nural Yüksel, Ni̇hat Ayyildiz

Turkish Journal of Mathematics

In the present paper, the geometrical instantaneous invariants of the motion $H_{_{m}}/H_{_{f}}\ $in dual Lorentzian $3$-space are determined. Depending on this, the dual Lorentzian instantaneous screw axis of the motion of $K_{_{m}}$ with respect to the dual pseudohyperbolic space $K_{_{m}}$ is constructed. On the other hand, we show that, in each position of $H_{_{m}}$, the fixed and moving axodes have the instantaneous screw axis of this position in common. We also give relations between the geodetic curvature and the curvature of the polodes.


Planar Embedding Of Trees On Point Sets Without The General Position Assumption, Asghar Asgharian Sardroud, Alireza Bagheri Jan 2015

Planar Embedding Of Trees On Point Sets Without The General Position Assumption, Asghar Asgharian Sardroud, Alireza Bagheri

Turkish Journal of Mathematics

The problem of point-set embedding of a planar graph $G$ on a point set $P$ in the plane is defined as finding a straight-line planar drawing of $G$ such that the nodes of $G$ are mapped one to one on the points of $P$. Previous works in this area mostly assume that the points of $P$ are in general position, i.e. $P$ does not contain any three collinear points. However, in most of the real applications we cannot assume the general position assumption. In this paper, we show that deciding the point-set embeddability of trees without the general position assumption …


On The Block Sequence Space $L_P(E)$ And Related Matrix Transformations, Davoud Foroutannia Jan 2015

On The Block Sequence Space $L_P(E)$ And Related Matrix Transformations, Davoud Foroutannia

Turkish Journal of Mathematics

The purpose of the present study is to introduce the sequence space $$l_p(E)=\left\{ x=(x_n)_{n=1}^{\infty}\;:\; \sum_{n=1}^{\infty} \left \sum_{j\in E_n}x_j\right ^p


Generalized Heineken--Mohamed Type Groups, Orest Artemovych Jan 2015

Generalized Heineken--Mohamed Type Groups, Orest Artemovych

Turkish Journal of Mathematics

We prove that a torsion group G with all subgroups subnormal is a nilpotent group or G=N(A_1 \times \cdots \times A_n) is a product of a normal nilpotent subgroup N and p_i-subgroups A_i, where A_i=A_1^{(i)} \cdots A_{m_i}^{(i)} \lhd G, A_j^{(i)} is a Heineken--Mohamed type group, and p_1, \ldots, p_n are pairwise distinct primes (n\geq 1; i=1, ... ,n; j=1, ... ,m_i and m_i are positive integers).


Coloring Hypercomplete And Hyperpath Graphs, Yusuf Ci̇van, Demet Taylan Jan 2014

Coloring Hypercomplete And Hyperpath Graphs, Yusuf Ci̇van, Demet Taylan

Turkish Journal of Mathematics

Given a graph G with an induced subgraph H and a family F of graphs, we introduce a (hyper)graph H_H(G;F)=(V_H, E_H), the hyper-H (hyper)graph of G with respect to F, whose vertices are induced copies of H in G, and \{H_1,H_2,\ldots,H_r\} \in E_H if and only if the induced subgraph of G by the set \cup_{i=1}^r H_i is isomorphic to a graph F in the family F, and the integer r is the least integer for F with this property. When H is a k-complete or a k-path of G, we abbreviate H_{K_k}(G;F) and H_{P_k}(G;F) to H_k(G;F) and HP_k(G;F), respectively. …


Euler-Seidel Matrices Over F_P, Nesri̇n Tutaş Jan 2014

Euler-Seidel Matrices Over F_P, Nesri̇n Tutaş

Turkish Journal of Mathematics

A Euler--Seidel matrix is determined by an infinite sequence whose elements are given by recursion. The recurrence relations are investigated for numbers and polynomials such as hyperharmonics, Lucas numbers, and Euler and Genocchi polynomials. Linear recurring sequences in finite fields are employed, for instance, in coding theory and in several branches of electrical engineering. In this work, we define the period of a Euler--Seidel matrix over a field F_p with p elements, where p is a prime number. We give some results for the matrix whose initial sequence is \{s_r(n)\}_{n=0}^{\infty}, where s_r(n)=\sum_{k=0}^n {\binom{n}{k}}^r, n \geq 0, and r is a …


On Betti Series Of The Universal Modules Of Second Order Derivations Of \Frac{K[X_1,X_2,...,X_S]}{(F)}, Ali̇ Erdoğan, Hali̇se Meli̇s Teki̇n Akçi̇n Jan 2014

On Betti Series Of The Universal Modules Of Second Order Derivations Of \Frac{K[X_1,X_2,...,X_S]}{(F)}, Ali̇ Erdoğan, Hali̇se Meli̇s Teki̇n Akçi̇n

Turkish Journal of Mathematics

Let R be a coordinate ring of an affine irreducible curve represented by \frac{k[x_1,x_2,...,x_s]}{(f)} and m be a maximal ideal of R. In this article, the Betti series of \Omega_2(R_m) is studied. We proved that the Betti series of \Omega_2(R_m), where \Omega_2(R_m) denotes the universal module of second order derivations of R_m, is a rational function under some conditions.


Some Results On T-Noncosingular Modules, Rachid Tribak Jan 2014

Some Results On T-Noncosingular Modules, Rachid Tribak

Turkish Journal of Mathematics

The notion of T-noncosingularity of a module has been introduced and studied recently. In this article, a number of new results of this property are provided. It is shown that over a commutative semilocal ring R such that Jac(R) is a nil ideal, every T-noncosingular module is semisimple. We prove that for a perfect ring R, the class of T-noncosingular modules is closed under direct sums if and only if R is a primary decomposable ring. Finitely generated T-noncosingular modules over commutative rings are shown to be precisely those having zero Jacobson radical. We also show that for a simple …


A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan Jan 2014

A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan

Turkish Journal of Mathematics

In this paper we call a ring R \delta_r-clean if every element is the sum of an idempotent and an element in \delta(R_R) where \delta(R_R) is the intersection of all essential maximal right ideals of R. If this representation is unique (and the elements commute) for every element we call the ring uniquely (strongly) \delta_r-clean. Various basic characterizations and properties of these rings are proved, and many extensions are investigated and many examples are given. In particular, we see that the class of \delta_r-clean rings lies between the class of uniquely clean rings and the class of exchange rings, and …


On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya Jan 2014

On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya

Turkish Journal of Mathematics

Let R be a ring and G a group. An R-module A is said to be Artinian-by-(finite rank) if Tor_R(A) is Artinian and A/ Tor_R(A) has finite R-rank. We study a module A over a group ring RG such that A/C_A(H) is Artinian-by-(finite rank) (as an R-module) for every proper subgroup H.


On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo Jan 2014

On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo

Turkish Journal of Mathematics

The group HS:2 is the full automorphism group of the Higman--Sims group HS. The groups 2^{4.}S_6 and 2^{5.}S_6 are maximal subgroups of HS and HS:2, respectively. The group 2^{4.}S_6 is of order 11520 and 2^{5.}S_6 is of order 23040 and each of them is of index 3 850 in HS and HS:2, respectively. The aim of this paper is to first construct \overline{G} = 2^{5.}S_6 as a group of the form 2^{4.}S_6.2 (that is, \overline{G} = G_1.2) and then compute the character tables of these 2 nonsplit extension groups by using the method of Fischer--Clifford theory. We will show that …


On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan Jan 2014

On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan

Turkish Journal of Mathematics

In this paper, we consider Finsler metrics defined by a Riemannian metric and a 1-form on a manifold. We study these metrics with vanishing S-curvature. We find some conditions under which such a Finsler metric is Berwaldian or locally Minkowskian.


Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz Jan 2014

Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz

Turkish Journal of Mathematics

In this paper we review the Spin(7) geometry in relation to solvmanifolds. Starting from a 7-dimensional nilpotent Lie group N endowed with an invariant G_2 structure, we present an example of a homogeneous conformally parallel Spin(7) metric on an associated solvmanifold. It is thought that this paper could lead to very interesting and exciting areas of research and new results in the direction of (locally conformally) parallel Spin(7) structures.


Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik Jan 2014

Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik

Turkish Journal of Mathematics

An almost Clifford and an almost Cliffordian manifold is a G--structure based on the definition of Clifford algebras. An almost Clifford manifold based on O:= Cl (s,t) is given by a reduction of the structure group GL(km, R) to GL(m, O), where k=2^{s+t} and m \in N. An almost Cliffordian manifold is given by a reduction of the structure group to GL(m, O) GL(1, O). We prove that an almost Clifford manifold based on O is such that there exists a unique subordinated connection, while the case of an almost Cliffordian manifold based on O is more rich. A class …


Global Existence, Uniform Decay, And Exponential Growth Of Solutions For A System Of Viscoelastic Petrovsky Equations, Faramarz Tahamtani, Amir Peyravi Jan 2014

Global Existence, Uniform Decay, And Exponential Growth Of Solutions For A System Of Viscoelastic Petrovsky Equations, Faramarz Tahamtani, Amir Peyravi

Turkish Journal of Mathematics

In this paper, we study the initial-boundary value problem for a system of nonlinear viscoelastic Petrovsky equations. Introducing suitable perturbed energy functionals and using the potential well method we prove uniform decay of solution energy under some restrictions on the initial data and the relaxation functions. Moreover, we establish a growth result for certain solutions with positive initial energy.


Scattering Data In An Inverse Scattering Problem On The Semi-Axis For A First-Order Hyperbolic System, Mansur Ismailov, İbrahi̇m Teki̇n Jan 2014

Scattering Data In An Inverse Scattering Problem On The Semi-Axis For A First-Order Hyperbolic System, Mansur Ismailov, İbrahi̇m Teki̇n

Turkish Journal of Mathematics

The inverse scattering problem for the first-order hyperbolic system on the semi-axis in the case of 2 incident and 2 scattered waves under consideration of 2 problems with the same given incident waves and different boundary conditions is considered. The scattering data on the semi-axis are given in terms of the scattering operator on the whole axis for the same system with the coefficients, which are extended in the whole axis by zero.


Kernel Operators On The Upper Half-Space: Boundedness And Compactness Criteria, Usman Ashraf, Muhammad Asif, Alexander Meskhi Jan 2014

Kernel Operators On The Upper Half-Space: Boundedness And Compactness Criteria, Usman Ashraf, Muhammad Asif, Alexander Meskhi

Turkish Journal of Mathematics

We establish necessary and sufficient conditions on a weight v governing the trace inequality \hat{K}f _{L^q_v(\hat{E})} \leq C f _{L^p(E)}, where E is a cone on a homogeneous group, \hat{E}: = E \times R_+ and \hat{K} is a positive kernel operator defined on \hat{E}. Compactness criteria for this operator are also established.


On Kakutani--Krein And Maeda--Ogasawara Spaces, Zafer Ercan, Neşet Özkan Tan Jan 2014

On Kakutani--Krein And Maeda--Ogasawara Spaces, Zafer Ercan, Neşet Özkan Tan

Turkish Journal of Mathematics

Let E be an Archimedean Riesz space. It is shown that the Kakutani--Krein space of the center of the Dedekind completion of E and the Maeda--Ogasawara space of E are homeomorphic. By applying this, we can reprove a Banach Stone type theorem for C^{\infty}(S) spaces, where S is a Stonean space.


A Characterization Of Certain Geodesic Hyperspheres In Complex Projective Space, Juan De Dios Perez, Y Oung Jin Suh Jan 2014

A Characterization Of Certain Geodesic Hyperspheres In Complex Projective Space, Juan De Dios Perez, Y Oung Jin Suh

Turkish Journal of Mathematics

We characterize geodesic hyperspheres of radius r such that cot^2(r)=\frac{1}{2} as the unique real hypersurfaces in complex projective space whose structure Jacobi operator satisfies a pair of conditions.


On Direct Products Of S-Posets Satisfying Flatness Properties, Roghaieh Khosravi Jan 2014

On Direct Products Of S-Posets Satisfying Flatness Properties, Roghaieh Khosravi

Turkish Journal of Mathematics

In this paper we characterize pomonoids over which various flatness properties of S-posets are preserved under direct products.


Gonality Of Curves With A Singular Model On An Elliptic Quadric Surface, Edoardo Ballico Jan 2014

Gonality Of Curves With A Singular Model On An Elliptic Quadric Surface, Edoardo Ballico

Turkish Journal of Mathematics

Let W \subset P^3 be a smooth quadric surface defined over a perfect field K and with no line defined over K (e.g., an elliptic quadric surface over a finite field). In this note we study the gonality over K of smooth curves with a singular model contained in W and with mild singularities.


Moment Equalities For Sums Of Random Variables Via Integer Partitions And Faà Di Bruno's Formula, Dietmar Ferger Jan 2014

Moment Equalities For Sums Of Random Variables Via Integer Partitions And Faà Di Bruno's Formula, Dietmar Ferger

Turkish Journal of Mathematics

We give moment equalities for sums of independent and identically distributed random variables including, in particular, centered and specifically symmetric summands. Two different types of proofs, combinatorial and analytical, lead to 2 different types of formulas. Furthermore, the combinatorial method allows us to find the optimal lower and upper constants in the Marcinkiewicz--Zygmund inequalities in the case of even moment-orders. Our results are applied to give elementary proofs of the classical central limit theorem (CLT) and of the CLT for the empirical bootstrap. Moreover, we derive moment and exponential inequalities for self-normalized sums.


Horizontally Submersions Of Contact Cr-Submanifolds, Fortune Massamba, Tshikunguila Tshikuna-Matamba Jan 2014

Horizontally Submersions Of Contact Cr-Submanifolds, Fortune Massamba, Tshikunguila Tshikuna-Matamba

Turkish Journal of Mathematics

In this paper, we discuss some geometric properties of almost contact metric submersions involving symplectic manifolds. We show that the structures of quasi-K-cosymplectic and quasi-Kenmotsu manifolds are related to (1, 2)-symplectic structures. For horizontally submersions of contact CR-submanifolds of quasi-K-cosymplectic and quasi-Kenmotsu manifolds, we study the principal characteristics and prove that their total spaces are CR-product. Curvature properties between curvatures of quasi-K-cosymplectic and quasi-Kenmotsu manifolds and the base spaces of such submersions are also established. We finally prove that, under a certain condition, the contact CR-submanifold of a quasi Kenmotsu manifold is locally a product of a totally geodesic leaf …


On A Tower Of Garcia And Stichtenoth, Seher Tutdere Jan 2014

On A Tower Of Garcia And Stichtenoth, Seher Tutdere

Turkish Journal of Mathematics

In 2003, Garcia and Stichtenoth constructed a recursive tower F = (F_n)_{n \geq 0} of algebraic function fields over the finite field F_q, where q = l^r with r \geq 1 and l > 2 is a power of the characteristic of F_q. They also gave a lower bound for the limit of this tower. In this paper, we compute the exact value of the genus of the algebraic function field F_n/F_q for each n \geq 0. Moreover, we prove that when q = 2^k, with k \geq 2, the limit of the tower F attains the lower bound given by …


Two-Weighted Norm Inequality On Weighted Morrey Spaces, Xiaofeng Ye, Tengfei Wang Jan 2014

Two-Weighted Norm Inequality On Weighted Morrey Spaces, Xiaofeng Ye, Tengfei Wang

Turkish Journal of Mathematics

Let u and \omega be weight functions. We shall introduce the weighted Morrey spaces L^{p,\kappa} (\omega) and investigate the sufficient condition and necessary condition about the 2-weighted boundedness of the Hardy--Littlewood maximal operator.


Homological Dimensions Of Complexes Related To Cotorsion Pairs, Chongqing Wei, Limin Wang, Husheng Qiao Jan 2014

Homological Dimensions Of Complexes Related To Cotorsion Pairs, Chongqing Wei, Limin Wang, Husheng Qiao

Turkish Journal of Mathematics

Let (A, B) be a cotorsion pair in R-Mod. We define and study notions of A dimension and B dimension of unbounded complexes, which is given by means of dg-projective resolution and dg-injective resolution, respectively. As an application, we extend the Gorenstein flat dimension of complexes, which was defined by Iacob. Gorenstein cotorsion, FP-projective, FP-injective, Ding projective, and Ding injective dimension are also extended from modules to complexes. Moreover, we characterize Noetherian rings, von Neumann regular rings, and QF rings by the FP-projective, FP-injective, and Ding projective (injective) dimension of complexes, respectively.


Norden Structures Of Hessian Type, Arif Salimov, Aydin Gezer Jan 2014

Norden Structures Of Hessian Type, Arif Salimov, Aydin Gezer

Turkish Journal of Mathematics

In this paper, we show that Kähler (para-Kähler) manifolds admit a Norden--Hessian metric h = \nabla^2f if the function f is holomorphic (para-holomorphic), and we further consider the existence condition of para-Kähler structures for Norden--Hessian metrics.


Adapted Basic Connections To A Certain Subfoliation On The Tangent Manifold Of A Finsler Space, Adelina Manea, Cristian Ida Jan 2014

Adapted Basic Connections To A Certain Subfoliation On The Tangent Manifold Of A Finsler Space, Adelina Manea, Cristian Ida

Turkish Journal of Mathematics

On the slit tangent manifold TM^0 of a Finsler space (M,F) there are given some natural foliations as vertical foliation and some other fundamental foliations produced by the vertical and horizontal Liouville vector fields, see [A. Bejancu, H. R. Farran, Finsler Geometry and Natural Foliations on the Tangent Bundle, Rep. Math. Physics 58, No. 1 (2006), 131--146]. In this paper we consider a (n,2n-1)-codimensional subfoliation (F_V,F_{\Gamma}) on TM^0 given by vertical foliation F_V and the line foliation spanned by vertical Liouville vector field \Gamma and we give a triplet of basic connections adapted to this subfoliation.