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Full-Text Articles in Physical Sciences and Mathematics

Criteria Of Le Page Type In Involutive Banach Algebras, Abdellah El Kinani, Mohamed Oudadess Jan 1999

Criteria Of Le Page Type In Involutive Banach Algebras, Abdellah El Kinani, Mohamed Oudadess

Turkish Journal of Mathematics

The Le Page inequality in Banach algebras is \parallel xy \parallel\leq\alpha\parallel yx\parallel. We consider inequalities where a linear involution appears and has consequences on the involution itself and commutativity results.^1


Countable Dense Homogeneous Bıtopologıcal Spaces, Abdalla Tallafha, Adnan Al-Bsoul, Ali̇ Ahmad Fora Jan 1999

Countable Dense Homogeneous Bıtopologıcal Spaces, Abdalla Tallafha, Adnan Al-Bsoul, Ali̇ Ahmad Fora

Turkish Journal of Mathematics

In this paper we shall introduce the concept of being countable dense homogeneous bitopological spaces and define several kinds of this concept. We shall give some results concerning these bitopological spaces and their relations. Also, we shall prove that all of these bitopological spaces satisfying the axioms p-T_0 and p-T_1.


Some Asymptotic Estimates For The Instability Intervals Of Hill's Equation, Haskiz Coşkun Jan 1999

Some Asymptotic Estimates For The Instability Intervals Of Hill's Equation, Haskiz Coşkun

Turkish Journal of Mathematics

In this study, some asymptotic estimates for the length of the instability intervals of Hill's equation, y''(t)+(\lambda -q(t))y(t)=0, are derived by means of an auxiliary eigenvalue problem under various assumptions on the Fourier coefficients of the potential q.


Univalent Harmonic Mappings Onto Half Planes, Meti̇n Öztürk Jan 1999

Univalent Harmonic Mappings Onto Half Planes, Meti̇n Öztürk

Turkish Journal of Mathematics

We consider the class S_H(D,\Omega ) of complex functions f which are univalent, harmonic, sense preserving on a simple connected domain D\neq {\Bbb C} \ containing the origin, satisfy f(0)=a_0, f_{\bar z}(0)=0a,\ a\in {\Bbb R}\}. In particularly, we describe the closure \overline{S_H(D,\Omega )} of S_H(D,\Omega ) and characterize its extreme points, as well as sharp estimates for coefficients and distortion theorems.


Generalized Solutions Of A Class Of Linear And Quasi-Linear Degenerated Hyperbolic Equations, Rossitza Semerdjieva Jan 1999

Generalized Solutions Of A Class Of Linear And Quasi-Linear Degenerated Hyperbolic Equations, Rossitza Semerdjieva

Turkish Journal of Mathematics

The equation $L(u):=k(y)u_{xx}-\partial_y(\ell(y)u_y)+r(x,y)u=f(x,y,u),$ where $k(y)>0, \ell(y)>0$ for $y>0,k(0)=\ell(0)=0$ and $lim_{y\rightarrow 0}k(y)/\ell(y)$ exists, is strictly hyperbolic for $y>0$ and its order degenerates on the line $y=0$. We consider the boundary value problem $Lu=f(x,y,u)$ in $G, u\mid_{AC}=0$, where $G$ is a simply connected domain in $R^2$ with piecewise smooth boundary $\partial G=AB\cup AC\cup BC; AB=\{(x,0): 0\leq x\leq 1\}, AC : x=F(y) =\int_0^y(k(t)/\ell (t))^{1/2}dt$ and $BC: x=1-F(y)$ are characteristic curves. The existence and uniqueness of a generalized solution to this problem are proved in the linear case (where $f=f(x,y));$ the nonlinear case is treated by using the Schauder Fixed …


The Isometries Of The Bochner Space L^P(\Mu,H), Bahatti̇n Cengi̇z Jan 1999

The Isometries Of The Bochner Space L^P(\Mu,H), Bahatti̇n Cengi̇z

Turkish Journal of Mathematics

In this article, the known characterization of the surjective linear isometries of the Bochner space $L^p(\mu, H)$, for a $\sigma$-finite measure $\mu$ and an arbitrary Hilbert space $H$, in terms of regular set isomorphisms of the $\sigma$-algebra involved and strongly measurable families of surjective isometries of $H$, is extended to arbitrary measures.


Modular Symmetry Classes Of Tensors, M. Shahryari, M. A. Shahabi Jan 1999

Modular Symmetry Classes Of Tensors, M. Shahryari, M. A. Shahabi

Turkish Journal of Mathematics

We introduce the notion of modular symmetry classes of tensors and give a necessary and sufficient condition for a modular symmetry class of tensors associated with the full symmetric group to be non-zero. Then we use modular symmetry classes of tensors to study the polynomial representations of $GL(V)$, where $V$ is a vector space over a field of characterisitic $p$. At the end we introduce a non-degenerate bilinear form on a modular symmetry class. Some problems are also given.


Some Theorems Involving Inequalities On P-Valent Functions, Hüseyi̇n Irmak, Ömer Faruk Çeti̇n Jan 1999

Some Theorems Involving Inequalities On P-Valent Functions, Hüseyi̇n Irmak, Ömer Faruk Çeti̇n

Turkish Journal of Mathematics

In this paper, some theorems involving inequalities on $p$-valent functions (that is $p$-valenty close-to-convex functions, $p$-valently starlike functions, and $p$-valently convex functions) are given. Moreover, some applications in the theorems which are important for geometric function theory are also included. Keywords: Analytic, $p$-valent, $p$-valently colse-to-convex functions, $p$-valently starlike functions, $p$-valently convex functions, open unit disk, and Jack's Lemma.


On The Asymptotic Behavior Of Heegner Points, Jan Nekovar, Norbert Schappacher Jan 1999

On The Asymptotic Behavior Of Heegner Points, Jan Nekovar, Norbert Schappacher

Turkish Journal of Mathematics

We prove that all but finitely many Heegner points on a given modular elliptic curve (or, more generally, on a given quotient of the modular Jacobian variety $J_0(N)$) are of infinite order in the Mordell-Weil group where they naturally live, i.e., over the corresponding ring class field.


A New Approach To Immersion Theory, Colin Rourke, Brian Sanderson Jan 1999

A New Approach To Immersion Theory, Colin Rourke, Brian Sanderson

Turkish Journal of Mathematics

No abstract provided.


Seiberg-Witten Invariants Of Mapping Tori,Symplectic Fixed Points, And Lefschetz Numbers, Dietmar A. Salamon Jan 1999

Seiberg-Witten Invariants Of Mapping Tori,Symplectic Fixed Points, And Lefschetz Numbers, Dietmar A. Salamon

Turkish Journal of Mathematics

No abstract provided.


Simply Connected Symplectic 4-Manifolds Withpositive Signature, Andras I. Stipsicz Jan 1999

Simply Connected Symplectic 4-Manifolds Withpositive Signature, Andras I. Stipsicz

Turkish Journal of Mathematics

No abstract provided.


Virtual Neighborhoods And Pseudo-Holomorphic Curves, Yongbin Ruan Jan 1999

Virtual Neighborhoods And Pseudo-Holomorphic Curves, Yongbin Ruan

Turkish Journal of Mathematics

No abstract provided.


Cycloidal Normal Subgroups Of Hecke Groups Of Finite Index, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m Jan 1999

Cycloidal Normal Subgroups Of Hecke Groups Of Finite Index, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m

Turkish Journal of Mathematics

Cycloidal normal subgroups, that is, subgroups with only one cusp, of finite index of Hecke groups, which have been introduced by E. Hecke, and can be thought of as some kind of generalisation of the well-known modular group, are studied. It is shown that they correspond to cyclic quotients of Hecke groups and therefore have non-compact associated Riemann surfaces with a cusp. Finally, their total number have been formulated.


Augmented Noetherian Graded Modules, Mashhoor Refai̇ Jan 1999

Augmented Noetherian Graded Modules, Mashhoor Refai̇

Turkish Journal of Mathematics

Let $G$ be a multiplicative group with identity $e$, and let $R$ be an associative $G$-graded ring with unity 1. In this paper we study the augmented graded Noetherian modules and try to give some relationships between the Noetherian modules in the category $R-Agr$ and the Noetherian modules in the category $R_e-gr$.


Structure Of M-Dimensional Implicitly Defined Surfaces In N-Dimensional Euclidean Space E_N, Alla Borisovna Kotlyar Jan 1999

Structure Of M-Dimensional Implicitly Defined Surfaces In N-Dimensional Euclidean Space E_N, Alla Borisovna Kotlyar

Turkish Journal of Mathematics

We consider the structure of the surface in the given point, if we vary all its normals in this point.


Two Lemmas On Formal Power Series, Kazim İlhan İkeda, Masatoshi İkeda Jan 1999

Two Lemmas On Formal Power Series, Kazim İlhan İkeda, Masatoshi İkeda

Turkish Journal of Mathematics

Let $L$ be a local field and $\tilde{L}$ the completion of the maximal unramified extension of $L$. In this short note, we prove \noindent (I) the sequences \noindent (1$^{\prime\prime}$) $0\rightarrow {\cal O}_L$[[$X_1,\ldots,X_n$]]$\rightarrow{\cal O}_{\tilde{L}}$[[$X_1,\ldots,X_n$]] $\stackrel{\phi_L-1}{\ra}{\cal O}_{\tilde{L}}$[[$X_1,\ldots,X_n$]]$\rightarrow 0$ \noindent and \noindent (2$^{\prime\prime}$) $1\rightarrow {\cal O}_L$[[$X_1,\ldots,X_n$]]$^x\rightarrow{\cal O}_{\tilde{L}}$[[$X_1,\ldots,X_n$]] $^x\stackrel{\phi_L-1}{\ra}{\cal O}_{\tilde{L}}$[[$X_1,\ldots,X_n$]]$\rightarrow 1$ \noindent are exact, where $\theta_L$ is the Frobenius automorphism over $L$ applied on the coefficients of ${\cal O}_{\tilde{L}}$[[$X_1,\ldots, X_n$]], and $\theta_L-1$ respectively denotes the mapping $\alpha\mapsto\alpha^{\theta L}-\alpha$ for \noindent (1$^{\prime\prime}$) and $\epsilon\mapsto\frac{\epsilon^{\phi}L}{\epsilon}$ for (2$^{\prime\prime}$); \noindent (II) ${\cal C}^{\circ}(\tilde{L},h)$ being the group the Coleman power series of degree 0, the sequence $$ 1\rightarrow {\cal …


A Survey On Drinfeld Modular Forms, Ernst-Ulrich Gekeler Jan 1999

A Survey On Drinfeld Modular Forms, Ernst-Ulrich Gekeler

Turkish Journal of Mathematics

No abstract provided.


The Structure Of A Solvmanifold's Heegaard Splittings, Darly Cooper, Martin Scharlemann Jan 1999

The Structure Of A Solvmanifold's Heegaard Splittings, Darly Cooper, Martin Scharlemann

Turkish Journal of Mathematics

No abstract provided.


A Fake Cusp And A Fishtail, Selman Akbulut Jan 1999

A Fake Cusp And A Fishtail, Selman Akbulut

Turkish Journal of Mathematics

No abstract provided.


Planar Linkages And Algebraic Sets, Henry C. King Jan 1999

Planar Linkages And Algebraic Sets, Henry C. King

Turkish Journal of Mathematics

No abstract provided.


A Program To Search For Homotopy 3-Spheres, Michael Greene, Colin Rouke Jan 1999

A Program To Search For Homotopy 3-Spheres, Michael Greene, Colin Rouke

Turkish Journal of Mathematics

No abstract provided.


Canonical Framings For 3 -Manifolds, Rob Kirby, Paul Melvin Jan 1999

Canonical Framings For 3 -Manifolds, Rob Kirby, Paul Melvin

Turkish Journal of Mathematics

No abstract provided.


On Symplectic Fillings Of 3-Manifolds, Paola Lisca Jan 1999

On Symplectic Fillings Of 3-Manifolds, Paola Lisca

Turkish Journal of Mathematics

No abstract provided.


Left Adjoint Of Pullback Cat^1 -Groups, Murat Alp Jan 1999

Left Adjoint Of Pullback Cat^1 -Groups, Murat Alp

Turkish Journal of Mathematics

In [1] we define the pullback Cat^1-groups and showed that the category of pullback Cat^1-groups is equivalent to the category of pullback crossed modules. In this paper we proved that the pullback Cat^1-group has a left adjoint which is the induced Cat^1-group. We also give the left adjoint construction.


Normal Subgroups And Elements Of H^{'}(\Lambda_Q), İsmai̇l Naci̇ Cangül Jan 1999

Normal Subgroups And Elements Of H^{'}(\Lambda_Q), İsmai̇l Naci̇ Cangül

Turkish Journal of Mathematics

In this study, we consider the normal subgroups of H^{'}(\lambda_q), where H(\lambda_q) denotes the Hecke groups. After recalling some results from [2], particularly on the group structure and on the relations with the power subgroups of H(\lambda_q), the even subgroup H_e(\lambda_q) of H(\lambda_q) is discussed. It is shown that H^{'}(\lambda_q) is a normal subgroup of H_e(\lambda_q) with index q. For this reason each subgroup of H^{'}(\lambda_q) consists of only even elements. H^{''}(\lambda_q) is also considered and it is concluded that it is the normal subgroup of H^{'}(\lambda_q) generated by all commutators of the elements of H^{'}(\lambda_q). Using the Kurosh subgroup …


On The Boundedness Of Integral Operators, İsmai̇l Eki̇nci̇oğlu, Isroil A. Ikromov Jan 1999

On The Boundedness Of Integral Operators, İsmai̇l Eki̇nci̇oğlu, Isroil A. Ikromov

Turkish Journal of Mathematics

In this paper, we consider integal operators defined by kernel functions. It is well known the boundedness of such kind of operators as Shur Lemma type statements. But, the norm of operators was estimated by two integrals of kernel function. We obtain estimation of operators norm by one integral of kernel function.


Geodesics In A Tensor Bundle, Abdullah Kopuzlu, Ari̇f A. Salimov Jan 1999

Geodesics In A Tensor Bundle, Abdullah Kopuzlu, Ari̇f A. Salimov

Turkish Journal of Mathematics

The main purpose of the present paper is to study geodesics in a tensor bundle T^{p}_q(M_n) with respect to the horizontal lift ^H\nabla of an affine connection \nabla .


A Stone's Representation Theorem And Some Applications, Eissa D. Habil Jan 1999

A Stone's Representation Theorem And Some Applications, Eissa D. Habil

Turkish Journal of Mathematics

In this paper, we prove the following form of Stone's representation theorem: Let \sum be a \sigma-algebra of subsets of a set X. Then there exists a totally disconnected compact Hausdorff space {\cal K} for which (\sum, \cup, \cap) and ({\cal C}({\cal K}), \cup ,\cap), where {\cal C}({\cal K}) denotes the set of all clopen subsets of {\cal K}, are isomorphic as Boolean algebras. Furthermore, by defining appropriate joins and meets of countable families in {\cal C}({\cal K}), we show that such an isomorphism preserves \sigma-completeness. Then, as a consequence of this result, we obtain the result that if ba(X,\sum) …


Segal Algebra As An Ideal In Its Second Dual Space, Heybet S. Mustafayev Jan 1999

Segal Algebra As An Ideal In Its Second Dual Space, Heybet S. Mustafayev

Turkish Journal of Mathematics

For a locally compact group G, let S(G) be a symmetric Segal algebra. We prove that S(G) is an ideal in its second dual space if and only if G is compact, where the second dual is equipped with an Arens multiplication.