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Dynamical System Topology Preserved In The Presence Of Noise, Judy A. Kennedy, James A. Yorke Jan 1998

Dynamical System Topology Preserved In The Presence Of Noise, Judy A. Kennedy, James A. Yorke

Turkish Journal of Mathematics

We first give a precise definition of the terms ``topological horseshoe'' and ``generalized quadrilateral'' and then examine the behavior of a homeomorphism F on a locally compact, separable, locally connected metric space X (X is usually a manifold in applications) such that F restricted to some generalized quadrilateral Q in X is a topological horseshoe map. For a set Q \subset X we define and describe (1) the permanent set Z of Q to be \{x\in X:F^n(x)\in Q for all integers n\}, and (2) the entrainment set of Q to be E(Q)=\{x\in X: F^{-n} (x)\in Q for all sufficiently large …


On The Cohomology Ring Of The Infinite Flag Manifold Lg/D, Cenap Özel Jan 1998

On The Cohomology Ring Of The Infinite Flag Manifold Lg/D, Cenap Özel

Turkish Journal of Mathematics

In this work, we discuss the calculation of cohomology rings of LG / T. First we describe the root system and Weyl group of LG, then we give some homotopy equivalences on the loop groups and homogeneous spaces, and investigate the cohomology ring structures of LSU_2 /T and \Omega SU_2. Also we prove that BGG-type operators correspond to partial derivation operators on the divided power algebras.


On 3 Dimensional Isotropic Submaniolds Of A Space From, Takehiro Itoh, Koichi Ogiue Jan 1998

On 3 Dimensional Isotropic Submaniolds Of A Space From, Takehiro Itoh, Koichi Ogiue

Turkish Journal of Mathematics

We study 3-dimensional isotropic submanifolds of a space form with low-dimensional first normal space


Cover And Contents Jan 1998

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.


Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz Jan 1998

Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz

Turkish Journal of Mathematics

Trenkler [13] described an iteration estimator. This estimator is defined as follows: for $0 < \gamma < 1/\lambda_i \max$ \[ \hat{\beta}_{m, \gamma} = \gamma \sum^m_{i=0} (1-\gamma X'X)^i X'y , \] where $\lambda_i$ are eigenvalues of $X'X$. In this paper a new estimator (generalized inverse estimator) is introduced based on the results of Tewarson [11]. A sufficient condition for the difference of mean square error matrices of least squares estimator and generalized inverse estimator to be positive definite (p.d.) is derived.


The Tachibana Operator And Transfer Of Lifts, Abdullah Mağden, Muhammet Kamali, Arif A. Salimov Jan 1998

The Tachibana Operator And Transfer Of Lifts, Abdullah Mağden, Muhammet Kamali, Arif A. Salimov

Turkish Journal of Mathematics

The main purpose of this paper is to investigate, using the Tachibana operator, transfer of the complete lifts of affinor structures along the cross-sections of the tangent and cotangent bundles.


Cover And Contents Jan 1998

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.


Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu Jan 1998

Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu

Turkish Journal of Mathematics

This paper is devoted to a study of timelike ruled surfaces in three dimensional Minkowski space obtained by a spacelike straight line moving along a timelike curve. The central point, the curve of striction and the distribution parameter of a timelike ruled surface in Minkowski 3-space are considered, and some theorems relating to their structure are obtained. In addition, some results about developable timelike ruled surfaces are also given.


About Some Classical Functional Equations, Nicolae Neamtu Jan 1998

About Some Classical Functional Equations, Nicolae Neamtu

Turkish Journal of Mathematics

The purpose of this paper is to give a new method of finding the solution of Lobashevsky's functional equation and those of other classical functional equations. At the beginning we present the properties of solution $f, \; f \neq 0$, of Lobachevsky's functional equation. Using only the boundedness property on $(-r, r)$, we deduce the continuity, convexity and differentiability properties of the solution.


An Improper Integral Representation Of Linnik's Probability Densities, A. (Bastiyali) Hayfavi̇ Jan 1998

An Improper Integral Representation Of Linnik's Probability Densities, A. (Bastiyali) Hayfavi̇

Turkish Journal of Mathematics

A representation of Linnik's Probability Densities by a contour integral distinct than the one given in [2] is obtained. An Improper integral representation of the same density functions is derived. An investigation into the exceptional set is achieved as well.


Cover And Contents Jan 1998

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.


On The Differential Prime Radical Of A Differential Ring, Djavvat Khadjiev, Fethi̇ Çallialp Jan 1998

On The Differential Prime Radical Of A Differential Ring, Djavvat Khadjiev, Fethi̇ Çallialp

Turkish Journal of Mathematics

In this paper we have obtained the following results for a differential ring (associative or nonassociative): (1) For a differential ring ({\cal D}-ring) we introduce definitions of a {\cal D}-prime {\cal D}-ideal, {\cal D}-semiprime {\cal D}-ideal and a strongly {\cal D}-nilpotent element. We define the {\cal D}-prime radical as the intersection of all {\cal D}-prime {\cal D}-ideals. For any {\cal D}-ring the {\cal D}-prime radical, the intersection of all {\cal D}-semiprime {\cal D}-semiprime {\cal D}-ideals and the set of all strongly {\cal D}-nilpotent elements are equal. (2) For a {\cal D}-ring we introduce a definition of an s-nilpotent {\cal D}-ideal. …


Normal Subgroups Of Hecke Groups On Sphere And, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m Jan 1998

Normal Subgroups Of Hecke Groups On Sphere And, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m

Turkish Journal of Mathematics

We use regular map theory to obtain all normal subgroups of Hecke groups of genus 0 and 1. The existence of a regular map corresponding uniquely to every normal subgroup of Hecke groups H(\lambda_q) is a result of Jones and Singerman, and it is frequently used here to obtain normal subgroups. It is found that when q is even, H(\lambda_q) has infinitely many normal subgroups on the sphere, while for odd q, this number is finite. The total number of normal subgroups of H(\lambda_q) on a torus is found to be either 0 or infinite. The latter case appears iff …


Fuzzy Ideals In Gamma Near-Rings, Young Bae Jun, Mehmet Sapanci, Mehmet Ali̇ Öztürk Jan 1998

Fuzzy Ideals In Gamma Near-Rings, Young Bae Jun, Mehmet Sapanci, Mehmet Ali̇ Öztürk

Turkish Journal of Mathematics

The aim of this paper is to introduce the notion of fuzzy left (resp. right) ideals of \Gamma-near-rings, and to study the related properties.


A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova Jan 1998

A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova

Turkish Journal of Mathematics

A Berry-Esseen bound for the number of empty cells in the scheme of independent and random allocation of balls of $s$ type into different cells is obtained.


Finite Direct Sums Of (D1)-Modules, Derya Keskin Jan 1998

Finite Direct Sums Of (D1)-Modules, Derya Keskin

Turkish Journal of Mathematics

In this paper we give necessary conditions for a finite direct sum of (D1)--modules to be a (D1)--module.


On Derived Equivalences And Local Structure Of Blocks Of Finite Groups, Markus Linckelmann Jan 1998

On Derived Equivalences And Local Structure Of Blocks Of Finite Groups, Markus Linckelmann

Turkish Journal of Mathematics

No abstract provided.


Crossed N-Cubes And N-Crossed Complexes Of Commutative Algebras, Z. Arvasi̇, M. Koçak Jan 1998

Crossed N-Cubes And N-Crossed Complexes Of Commutative Algebras, Z. Arvasi̇, M. Koçak

Turkish Journal of Mathematics

In this paper we will define crossed $\Bbb N$-cubes and n-crossed complexes of commutative algebras and construct a functor from the category of simplicial algebras to that of n-crossed complexes.


Pullbacks Of Crossed Modules And Cat^1-Groups, Murat Alp Jan 1998

Pullbacks Of Crossed Modules And Cat^1-Groups, Murat Alp

Turkish Journal of Mathematics

In this paper, wer define the pullback cat$^{1}$-groups and we showed that the category of bullback cat$^{1}$-group is equivalent to the category of pullback crossed modules. 1991 A. M. S. C.: 13D99, 16A99, 17B99, 18D35.


Derivation Of Separable Amplitude Equations By Multiple Scales Method, Mehmet Naci̇ Özer, Dursun Eser Jan 1998

Derivation Of Separable Amplitude Equations By Multiple Scales Method, Mehmet Naci̇ Özer, Dursun Eser

Turkish Journal of Mathematics

The method of multiple scales is used to derive separable nonlinear Schrödinger equations as amplitude equation from three component 2D nonlinear Klein-Gordon Equation. We further discuss the integrability of the derived separable amplitude equations and reduce them into finite dimensional Hamiltonian systems. Finally we give first integrals for the reduced systems.


The Dual Of The Bochner Space L^P(\Mu,E) For Arbitrary \Mu, Bahatti̇n Cengi̇z Jan 1998

The Dual Of The Bochner Space L^P(\Mu,E) For Arbitrary \Mu, Bahatti̇n Cengi̇z

Turkish Journal of Mathematics

Let $\mu$ be a finite measure, $E$ a Banach space, and $1\leq p


Direct Sums And The Schur Property, Betül Tanbay Jan 1998

Direct Sums And The Schur Property, Betül Tanbay

Turkish Journal of Mathematics

It is a known fact that $\ell^1$, the dual space of the null sequences $c_0$, has the Schur property, that is, weakly convergent sequences in $\ell^1$ are norm convergent. In this paper, we prove that if $(X_{\alpha})_{\alpha\in I}$ are Banach spaces and $X=(\oplus_{\alpha\in I}X_{\alpha})_1$ their $l_1$-sum, then the space $X$ has the Schur property iff each factor $X_{\alpha}$ has it.


Fibonacci Sequences In Finite Nilpotent Groups, Ramazan Di̇ki̇ci̇, Geoff C. Smith Jan 1997

Fibonacci Sequences In Finite Nilpotent Groups, Ramazan Di̇ki̇ci̇, Geoff C. Smith

Turkish Journal of Mathematics

We have proved that, for the 3-step Fibonacci recurrence and any finite p-group of exponent p and nilpotency class 3, the length of a fundamental period of any loop satisfying the recurrence must divide the period of the ordinary 3-step Fibonacci sequence in the field GF(p).


An Introduction To Topological Quantum Field Theories, Michael Atiyah Jan 1997

An Introduction To Topological Quantum Field Theories, Michael Atiyah

Turkish Journal of Mathematics

No abstract provided.


Critical Point Theory In Mathematics And In Mathematical Physics, Raoul Bott Jan 1997

Critical Point Theory In Mathematics And In Mathematical Physics, Raoul Bott

Turkish Journal of Mathematics

No abstract provided.


On Irreducible Simply-Connected 4-Manifolds, Zoltan Szabo Jan 1997

On Irreducible Simply-Connected 4-Manifolds, Zoltan Szabo

Turkish Journal of Mathematics

No abstract provided.


Seiberg-Witten \`{A} La Furuta And Genus Bounds For Classes With Divisibility, Jim Bryan Jan 1997

Seiberg-Witten \`{A} La Furuta And Genus Bounds For Classes With Divisibility, Jim Bryan

Turkish Journal of Mathematics

No abstract provided.


Casson's Invariant And Seiberg-Witten Gauge Theory, Weimin Chen Jan 1997

Casson's Invariant And Seiberg-Witten Gauge Theory, Weimin Chen

Turkish Journal of Mathematics

In this paper, the very first step is taken towards solving the recently proposed conjecture by Kronheimer and Mrowka [KM2] concerning the Casson's invariant of an oriented homology 3-sphere and its Seiberg-Witten Floer homology.


Seiberg-Witten Invariants When Reversing Orientation, Tedi Draghici Jan 1997

Seiberg-Witten Invariants When Reversing Orientation, Tedi Draghici

Turkish Journal of Mathematics

In this paper, the very first step is taken towards solving the recently proposed conjecture by Kronheimer and Mrowka [KM2] concerning the Casson's invariant of an oriented homology 3-sphere and its Seiberg-Witten Floer homology.


Seiberg-Witten Equations On R^8, Ayşe Hümeyra Bi̇lge, Tekin Dereli̇, Şahin Koçak Jan 1997

Seiberg-Witten Equations On R^8, Ayşe Hümeyra Bi̇lge, Tekin Dereli̇, Şahin Koçak

Turkish Journal of Mathematics

We show that there are no nontrivial solutions of the Seiberg-Witten equations on R^8 with constant standard {spin}^c structure.