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Full-Text Articles in Physical Sciences and Mathematics

On Homogeneous Riemann Boundary Value Problem, K. Kutlu Jan 1996

On Homogeneous Riemann Boundary Value Problem, K. Kutlu

Turkish Journal of Mathematics

In this work we consider homogeneous Riemann boundary value problem (BVP) on general open rectifiable curves. We prove certain estimates for Cauchy type integrals in terms of local moduli of continuity and local maximum of modulus, which allow us to describe the solvability of Riemann BVP with unbounded oscillating coefficients on a wide class of non-smooth rectifiable Jordan curves.


On Strongly Regular Rings, A. Kaya, F. Kuzucuoğlu Jan 1996

On Strongly Regular Rings, A. Kaya, F. Kuzucuoğlu

Turkish Journal of Mathematics

Some characterizations of strongly regular rings will be given. Let R be a ring and I(\neq R) a right ideal of R. If, for each pair of right ideals A and B of R, AB \subseteq I implies that either A \subseteq I or B \subseteq I, then I is called a prime right ideal (or equivalently, if aRb \ \ \not\subseteq I whenever a and b do not belong to I). I is strongly prime right ideal if, for each pair of a and b in R, aIb \subseteq I and ab \in I imply that either a \in …


Weak\Star- Invariantly Complemented Subspaces Of L^{\Infty}(1/\Omega) And Ideals Of L^{1}(\Omega) With A Bounded Approximate Identity, Z. Argün, C. Tonyali Jan 1996

Weak\Star- Invariantly Complemented Subspaces Of L^{\Infty}(1/\Omega) And Ideals Of L^{1}(\Omega) With A Bounded Approximate Identity, Z. Argün, C. Tonyali

Turkish Journal of Mathematics

For a locally compact group G let L^{1}(\omega) be the weighted group algebra and let X be a weak \star-closed translation invariant subspace of L^{\infty} (1/\omega). In this paper for a certain class of functions we show that the following conditions are equivalent: (i) X is topological invariantly complemented in L^{\infty}(1/\omega); (ii) X is invariantly complemented in L^{\infty}(1/\omega); (iii) The left ideal X_{\perp} has a bounded right approximate identity.


Extension Of Caristi-Kirk's Theorem, M. O. Diallo, M. Oudadess Jan 1996

Extension Of Caristi-Kirk's Theorem, M. O. Diallo, M. Oudadess

Turkish Journal of Mathematics

We give some extensions and/or improvements, to uniform spaces and to multi-valued mappings, of Caristi-Kirk's theorem.


Normal Boundary Value Problems For Differential Equations Of Higher Order, F. G. Maksudov, Z. I. Ismailov Jan 1996

Normal Boundary Value Problems For Differential Equations Of Higher Order, F. G. Maksudov, Z. I. Ismailov

Turkish Journal of Mathematics

In this work the arbitrary order differential operator expression of the form \imath (u) = \frac{\partial u (t)}{\partial t^n}+Au(t), where A is a bounded normal operator in the Hilbert Space H is considered in the Hilbert Space of vector functions L_2(H(0,1)). This paper describes all normal boundary value problem for the indicated diferential expression in terms of abstnract boundary conditions and determines a connection with other typea of boundary value problems.


T_2-Objects In Categories Of Filter And Local Filter Convergence Spaces, M. Baran Jan 1996

T_2-Objects In Categories Of Filter And Local Filter Convergence Spaces, M. Baran

Turkish Journal of Mathematics

There are various generalizations of the usual T_2 (Hausdorff) axiom of topology to an arbitrary topological category defined in [1]. In this paper, four more new generalizations of Hausdorff spaces are given in the topological categories. Moreover, the relationships among all of these T_2 structures and the ones given in [5] and [7] as well as some invariance properties of them are investigated in the categories of filter and local filter convergence spaces. Keywords: Topological Categories, T_2-objects, Filter Convergence Spaces.


On Conformally Flat Lorentzian Spaces Satisfying A Certain Condition On The Curvature Tensor, M. Erdoğan Jan 1996

On Conformally Flat Lorentzian Spaces Satisfying A Certain Condition On The Curvature Tensor, M. Erdoğan

Turkish Journal of Mathematics

In this paper we prove a local classification theorem for the conformally flat lorentzian spaces satisfying the condition R(X,Y)R=0.


On The Additive Group Structure Of Nonstandard Models Of Z, Ç. Gencer, M. Terzi̇ler Jan 1996

On The Additive Group Structure Of Nonstandard Models Of Z, Ç. Gencer, M. Terzi̇ler

Turkish Journal of Mathematics

Let \hat{Z} denote the inverse limit of finite cyclic groups and F_gZ the group where $F$ is a vector space over Q and + is defined by (a, x)+(b, y)=(a+b, x+y+g(a,b)) for some g: F\times F\rightarrow Z. In this paper we show that any nonstandard model Z^{\star} of Z is isomorphic to F_{\beta}Z for some \beta: F\rightarrow \hat{Z} where F=Z^{\star}/Z.


A Note On Double Sequences Of Fuzzy Numbers, E. Savaş Jan 1996

A Note On Double Sequences Of Fuzzy Numbers, E. Savaş

Turkish Journal of Mathematics

In this paper we introduce double convergent sequences of fuzzy numbers and we also study the space of double convergent sequences of fuzzy numbers.


Rings In Which Strongly Prime Right Ideals Are Finitely Generated, A. Kaya Jan 1996

Rings In Which Strongly Prime Right Ideals Are Finitely Generated, A. Kaya

Turkish Journal of Mathematics

Some properties of rings in which every strongly prime right ideal is finitely generated will be investigated, and sufficient conditions for such rings to be right noetherian will be given. Let R be an s-unital ring (i.e., a\in aR\cap Ra for each a\in R) and I(\neq R)a right ideal of R. If, for each right ideals A and B of R, AB\subseteq I implies that either A\subseteq I or B\subseteq I, then I is called a prime right ideal (or equivalently, if a\, R\,b \not\subseteq I whenever a and b do not belong to I). I is strongly prime if, …


A Property Of Meldrum Groups, A. O. Asar, S. Atlihan Jan 1996

A Property Of Meldrum Groups, A. O. Asar, S. Atlihan

Turkish Journal of Mathematics

In this work it is shown that the direct product of two Meldrum groups does not satisfy the normalizer condition. It is not known yet if the same result holds true for any two HM-groups.


The Group Structure Of Hecke Groups H(\Lambda_Q), İ. N. Cangül Jan 1996

The Group Structure Of Hecke Groups H(\Lambda_Q), İ. N. Cangül

Turkish Journal of Mathematics

In this work a new proof of the fact that the group structure of the Hecke groups is isomorphic to the free product of two cyclic groups of orders 2 and q is given The method used in the proof requires a result of A.M. Macbeath together with the notion of fundamental region. Also given are some new results on the parabolic points of Hecke groups, which still is an open problem.


Absolutely Representing Systems And Convolution Operators In The Complex Domain, Yu. F. Korobeinik Jan 1996

Absolutely Representing Systems And Convolution Operators In The Complex Domain, Yu. F. Korobeinik

Turkish Journal of Mathematics

The author suggests a method of characterizing of the kernel of a convolution-type operator. The method is based on the exact description of nontrivial expansions of zero of an absolutely representing system consisting of eigen vectors of some linear operator with continuous spectrum. The method suggested in the paper is applied to the characterization of the kernel of the convolution-type operator defined on some space of entire functions and to the factorization of such an operator.


(\Sigma, \Tau)- Lie Ideals In Prime Rings With Derivation, M. Soytürk Jan 1996

(\Sigma, \Tau)- Lie Ideals In Prime Rings With Derivation, M. Soytürk

Turkish Journal of Mathematics

Let R be a prime ring, char R\neq 2,3 \, \sigma, \tau : R\rightarrow R two automorphisms, U a nonzero (\sigma, \tau)- Lie ideal of R and o\neq d : R\rightarrow R$ a derivation such that \sigma d = d\sigma, \tau d = d\tau. In this paper we have proved the following results. (1) If d (U) \subset Z then U\subset Z (2) If d(U) \subset U and d^2 (U) \subset Z then U\subset Z.


On Homotopic, Non--Isomorphic Tight Contact Structures On 3-Manifolds, Paolo Lisca, Gordana Matic Jan 1996

On Homotopic, Non--Isomorphic Tight Contact Structures On 3-Manifolds, Paolo Lisca, Gordana Matic

Turkish Journal of Mathematics

No abstract provided.


A Survey Of Symplectic 4-Manifolds With B^+ = 1, Dusa Mcduff, Dietmar Salamon Jan 1996

A Survey Of Symplectic 4-Manifolds With B^+ = 1, Dusa Mcduff, Dietmar Salamon

Turkish Journal of Mathematics

No abstract provided.


Removable Singularities And A Vanishing Theorem For Seiberg-Witten Invariants, Dietmar Salamon Jan 1996

Removable Singularities And A Vanishing Theorem For Seiberg-Witten Invariants, Dietmar Salamon

Turkish Journal of Mathematics

No abstract provided.


Higher Genus Symplectic Invariants And Sigma Model Coupled With Gravity, Yongbin Ruan, Gang Tian Jan 1996

Higher Genus Symplectic Invariants And Sigma Model Coupled With Gravity, Yongbin Ruan, Gang Tian

Turkish Journal of Mathematics

No abstract provided.


Akbulut's Corks And H-Cobordisms Of Smooth, Simply Connected 4-Manifolds, Rob Kirby Jan 1996

Akbulut's Corks And H-Cobordisms Of Smooth, Simply Connected 4-Manifolds, Rob Kirby

Turkish Journal of Mathematics

No abstract provided.


Contact Structures And Foliations On 3-Manifolds, Yakov M. Eliashberg, William P. Thurston Jan 1996

Contact Structures And Foliations On 3-Manifolds, Yakov M. Eliashberg, William P. Thurston

Turkish Journal of Mathematics

No abstract provided.


Lectures On Seiberg-Witten Invariants, Selman Akbulut Jan 1996

Lectures On Seiberg-Witten Invariants, Selman Akbulut

Turkish Journal of Mathematics

No abstract provided.


The Multi-Monopole Equations For K\"Ahler Surfaces, James A. Bryan, Richard Wentworth Jan 1996

The Multi-Monopole Equations For K\"Ahler Surfaces, James A. Bryan, Richard Wentworth

Turkish Journal of Mathematics

The purpose of this paper is to introduce a natural generalization of the Seiberg-Witten equations having more than one Spinor field ("monopole") and to study the moduli space of solutions in the case of a K\"ahler surface. We find an explicit algebro-geometric construction of the moduli space. In the course of our construction, we prove an existence and uniqueness result for a generalization of the Kazdan-Warner equation.


The Minimal Genus Of An Embedded Surface Of Non-Negative Square In A Rational Surface, Daniel Ruberman Jan 1996

The Minimal Genus Of An Embedded Surface Of Non-Negative Square In A Rational Surface, Daniel Ruberman

Turkish Journal of Mathematics

No abstract provided.


Star Topological Groupoids, O. Mucuk Jan 1996

Star Topological Groupoids, O. Mucuk

Turkish Journal of Mathematics

In [4] a construction on topological groups was given. In this paper we generalize this costruction to more general topological groupoids and have a similar structure on the topological groupodis.


A Note On Intuitionistic Sets And Intuitionistic Points, D. Çoker Jan 1996

A Note On Intuitionistic Sets And Intuitionistic Points, D. Çoker

Turkish Journal of Mathematics

The purpose of this note is to define the so-called "intuitionistic sets" and "intuitionistic points", and obtain their fundamental properties.


A Note On The Geography Of Symplectic Manifolds, Andras Stipsicz Jan 1996

A Note On The Geography Of Symplectic Manifolds, Andras Stipsicz

Turkish Journal of Mathematics

No abstract provided.


Operations With The Periodic Decimal Expansions, H. Ardahan Jan 1996

Operations With The Periodic Decimal Expansions, H. Ardahan

Turkish Journal of Mathematics

In this paper, we prove the rules of direct addition and subtraction for the finite decimal expansions of fractions which are periodic. It has been shown that these rules are valid for the fractions which can be expanded as a periodic decimal with p figures in the period or have the mixed decimal part containing \nu non-periodic and p periodic figures. Also, it has been given a rule of multiplication for these periodic decimals by 10^{\nu}, \nu\in\Bbb N. Last of all, if a rational fraction has a period of length p, then it can be expressed by a decimal expansion, …


Configuration Spaces And Imbedding Invariants, Raoul Bott Jan 1996

Configuration Spaces And Imbedding Invariants, Raoul Bott

Turkish Journal of Mathematics

No abstract provided.


Relations Between Classes Of Dragilev Spaces (F_1)_{\Sigma} And (F_2)_{\Sigma} For Arbitrary Function F^{-1}_{1}\Circ F_2}, V. Kashirin, A. Vakulenko Jan 1996

Relations Between Classes Of Dragilev Spaces (F_1)_{\Sigma} And (F_2)_{\Sigma} For Arbitrary Function F^{-1}_{1}\Circ F_2}, V. Kashirin, A. Vakulenko

Turkish Journal of Mathematics

Necessary and sufficient condition under wich Dragilev classes (f_1)_{\sigma} and (f_2)_{\sigma} coincide have been found for an arbitrary function f^{-1}_{1}\circ f_2.


Linear Topologic Invariants And Their Applications To Isomorphic Classification Of Generalized Power Spaces, V. Zahariuta Jan 1996

Linear Topologic Invariants And Their Applications To Isomorphic Classification Of Generalized Power Spaces, V. Zahariuta

Turkish Journal of Mathematics

In the present survey generalized linear topological invariants are considered as a development of classical invariants of Kolmogorov and Pelczynski (approximative and diametral dimensions). It is realized a geometric idea to construct some new invariant characteristics by applying of classical characteristics (diameter or entropy-like characteristics) to some symplest interpolational constructions under neighborhoods, taken from a given basis of neighborhoods of zero. It is considered various applications to isomorphic classification of generalized power K\"{o}the spaces (in particular, tensor products of finite and infinite type power series spaces, spaces of analytic and infinitely differentiable vector-valued functions, spaces of analytic functions of several …