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Full-Text Articles in Physical Sciences and Mathematics

The New Method Of Determining Koebe Domains For The Class Of Typically Real Functions Under Montel's Normalization, Leopold Koczan, Pawel Zaprawa Jan 2014

The New Method Of Determining Koebe Domains For The Class Of Typically Real Functions Under Montel's Normalization, Leopold Koczan, Pawel Zaprawa

Turkish Journal of Mathematics

We consider the class T(r) of typically real functions with the normalization f(0)=0 and f(r)=r for a fixed r \in (0,1). In the limiting case, when r tends to 0, the class T(r) coincides with the class T of typically real functions normalized by f(0)=f'(0)-1=0. In 1980, Lewandowski and Miazga determined the Koebe domain for T(r), i.e. the set of the form \bigcap_{f\in T(r)} f(\Delta). They used the method applied earlier by Goodman. In this paper we present a new, complete method of determining this set. As a corollary, we obtain the Koebe set for T.


An Existence Result For A Quasilinear System With Gradient Term Under The Keller--Osserman Conditions, Dragos Patru Covei Jan 2014

An Existence Result For A Quasilinear System With Gradient Term Under The Keller--Osserman Conditions, Dragos Patru Covei

Turkish Journal of Mathematics

We use some new technical tools to obtain the existence of entire solutions for the quasilinear elliptic system of type \Delta _pu_i+h_i(\vert x\vert) \vert \nabla u_i\vert ^{p-1}=a_i(\vert x\vert ) f_i(u_{1},u_2) on R^N (N\geq 3, i=1,2) where N-1\geq p>1, \Delta_p is the p-Laplacian operator, and h_i, a_i, f_i are suitable functions. The results of this paper supplement the existing results in the literature and complete those obtained by Jesse D Peterson and Aihua W Wood (Large solutions to non-monotone semilinear elliptic systems, Journal of Mathematical Analysis and Applications, Volume 384, pages 284--292, 2011).


On Kapranov's Description Of \Overline{M}_{0,N} As A Chow Quotient, Noah Giansiracusa, William Danny Gillam Jan 2014

On Kapranov's Description Of \Overline{M}_{0,N} As A Chow Quotient, Noah Giansiracusa, William Danny Gillam

Turkish Journal of Mathematics

We provide a direct proof, valid in arbitrary characteristic, of the result originally proven by Kapranov over C that the Hilbert quotient (P^1)^n//_HPGL_2 and Chow quotient (P^1)^n//_{Ch}PGL_2 are isomorphic to \overline{M}_{0,n}. In both cases this is done by explicitly constructing the universal family of orbit closures and then showing that the induced morphism is an isomorphism onto its image. The proofs of these results in many ways reduce to the case n = 4; in an appendix we outline a formalism of this phenomenon relating to certain operads.


Oscillation Of Second Order Differential Equations With Mixed Nonlinearities, Zhiting Xu, Aijun Cheng Jan 2014

Oscillation Of Second Order Differential Equations With Mixed Nonlinearities, Zhiting Xu, Aijun Cheng

Turkish Journal of Mathematics

By refining the standard integral averaging technique, in this paper, new oscillation criteria as well as interval oscillation criteria are established for the second order delay differential equation with mixed nonlinearities \begin{equation*} (r(t) x^{\prime}(t) ^{\alpha-1}x^{\prime}(t))^{\prime}+q_0(t) x(\tau_0(t)) ^{\alpha-1}x(\tau_0(t)) +\sum\limits_{i = 1}^nq_i(t) x(\tau_i(t)) ^{\alpha_i-1}x(\tau_i(t)) = 0, \end{equation*} where \alpha>0, \alpha_i>0, i = 1,2,\cdots,n. Our results generalize and improve the known results in the literature. Examples are also given to illustrate the importance of our results.


Continuity Of Wigner-Type Operators On Lorentz Spaces And Lorentz Mixed Normed Modulation Spaces, Ayşe Sandikçi Jan 2014

Continuity Of Wigner-Type Operators On Lorentz Spaces And Lorentz Mixed Normed Modulation Spaces, Ayşe Sandikçi

Turkish Journal of Mathematics

We study various continuity properties for \tau-Wigner transform on Lorentz spaces and \tau-Weyl operators W_{\tau}^{a} with symbols belonging to appropriate Lorentz spaces. We also study the action of \tau-Wigner transform on Lorentz mixed normed modulation spaces.


Relaxed Elastic Line In A Riemannian Manifold, Gözde Özkan, Ahmet Yücesan Jan 2014

Relaxed Elastic Line In A Riemannian Manifold, Gözde Özkan, Ahmet Yücesan

Turkish Journal of Mathematics

We obtain a differential equation with 2 boundary conditions for a relaxed elastic line in a Riemannian manifold. This differential equation, which is found with respect to constant sectional curvature G, geodesic curvature \kappa, and 2 boundary conditions, gives a more direct and more geometric approach to questions concerning a relaxed elastic line in a Riemannian manifold. We give various theorems and results in terms of a relaxed elastic line. Consequently, we examine the concept of a relaxed elastic line in 2- and 3- dimensional space forms.


On Semiparallel Anti-Invariant Submanifolds Of Generalized Sasakian Space Forms, Ci̇han Özgür, Fatma Gürler, Cengi̇zhan Murathan Jan 2014

On Semiparallel Anti-Invariant Submanifolds Of Generalized Sasakian Space Forms, Ci̇han Özgür, Fatma Gürler, Cengi̇zhan Murathan

Turkish Journal of Mathematics

We consider minimal anti-invariant semiparallel submanifolds of generalized Sasakian space forms. We show that the submanifolds are totally geodesic under certain conditions.


Hausdorff Dimension Of The Graph Of The Error-Sum Function Of \Alpha-Lüroth Series, Haibo Chen, Wenbo Wang, Min Yu Jan 2014

Hausdorff Dimension Of The Graph Of The Error-Sum Function Of \Alpha-Lüroth Series, Haibo Chen, Wenbo Wang, Min Yu

Turkish Journal of Mathematics

Let \alpha be a countable partition of the unit interval [0,1]. In this paper, we will introduce the error-sum function of \alpha-Lüroth series and determine the Hausdorff dimension of its graph when the partition \alpha is eventually decreasing. Some other properties of the error-sum function are also investigated.


Coverings And Crossed Modules Of Topological Groups With Operations, Osman Mucuk, Tunçar Şahan Jan 2014

Coverings And Crossed Modules Of Topological Groups With Operations, Osman Mucuk, Tunçar Şahan

Turkish Journal of Mathematics

It is a well-known result of the covering groups that a subgroup G of the fundamental group at the identity of a semilocally simply connected topological group determines a covering morphism of topological groups with characteristic group G. In this paper we generalize this result to a large class of algebraic objects called topological groups with operations, including topological groups. We also prove that the crossed modules and internal categories within topological groups with operations are equivalent. This equivalence enables us to introduce the cover of crossed modules within topological groups with operations. Finally, we draw relations between the coverings …


Adjoints Of Rationally Induced Composition Operators On Bergman And Dirichlet Spaces, Aliakbar Goshabulaghi, Hamid Vaezi Jan 2014

Adjoints Of Rationally Induced Composition Operators On Bergman And Dirichlet Spaces, Aliakbar Goshabulaghi, Hamid Vaezi

Turkish Journal of Mathematics

We will state a connection between the adjoints of a vast variety of bounded operators on 2 different weighted Hardy spaces. We will apply it to determine the adjoints of rationally induced composition operators on Dirichlet and Bergman spaces.


\Xi^{\Perp}-Submanifolds Of Para-Sasakian Manifolds, Selcen Yüksel Perktaş, Mukut Mani Tripathi, Erol Kiliç, Sadik Keleş Jan 2014

\Xi^{\Perp}-Submanifolds Of Para-Sasakian Manifolds, Selcen Yüksel Perktaş, Mukut Mani Tripathi, Erol Kiliç, Sadik Keleş

Turkish Journal of Mathematics

Almost semiinvariant \xi^{\perp}-submanifolds of an almost paracontact metric manifold are defined and studied. Some characterizations of almost semiinvariant \xi^{\perp}-submanifolds and semiinvariant \xi^{\perp}-submanifolds are presented. A para-CR-structure is defined and it is proven that an almost semiinvariant \xi^{\perp}-submanifold of a normal almost paracontact metric (and hence para-Sasakian) manifold with the proper invariant distribution always possesses a para-\textit{CR}-structure. A counter example is also given. Integrability conditions for certain natural distributions arising on almost semiinvariant \xi^{\perp} -submanifolds are obtained. Finally, certain parallel operators on submanifolds are investigated.


An Alternative Approach To The Adem Relations In The Mod 2 Steenrod Algebra, Neşet Deni̇z Turgay Jan 2014

An Alternative Approach To The Adem Relations In The Mod 2 Steenrod Algebra, Neşet Deni̇z Turgay

Turkish Journal of Mathematics

The Leibniz--Hopf algebra F is the free associative algebra over Z on one generator S^n in each degree n>0, with coproduct given by \Delta(S^n) = \sum_{i+j=n} S^i \otimes S^j. We introduce a new perspective on the Adem relations in the mod 2 Steenrod algebra A_2 by studying the map \pi^\ast dual to the Hopf algebra epimorphism \pi: F \otimes Z/2 \to A_2. We also express Milnor's Hopf algebra conjugation formula in A_2^\ast in a different form and give a new approach for the conjugation invariant problem in A_2^\ast.


On A Generalization Of Kelly's Combinatorial Lemma, Aymen Ben Amira, Jamel Dammak, Hamza Si Kaddour Jan 2014

On A Generalization Of Kelly's Combinatorial Lemma, Aymen Ben Amira, Jamel Dammak, Hamza Si Kaddour

Turkish Journal of Mathematics

Kelly's combinatorial lemma is a basic tool in the study of Ulam's reconstruction conjecture. A generalization in terms of a family of t -elements subsets of a v -element set was given by Pouzet. We consider a version of this generalization modulo a prime p. We give illustrations to graphs and tournaments.


Generalized Derivations Centralizing On Jordan Ideals Of Rings With Involution, Lahcen Oukhtite, Abdellah Mamouni Jan 2014

Generalized Derivations Centralizing On Jordan Ideals Of Rings With Involution, Lahcen Oukhtite, Abdellah Mamouni

Turkish Journal of Mathematics

A classical result of Posner states that the existence of a nonzero centralizing derivation on a prime ring forces the ring to be commutative. In this paper we extend Posner's result to generalized derivations centralizing on Jordan ideals of rings with involution and discuss the related results. Moreover, we provide examples to show that the assumed restriction cannot be relaxed.


Generalized Derivations On Jordan Ideals In Prime Rings, Mahmoud El-Soufi, Ahmed Aboubakr Jan 2014

Generalized Derivations On Jordan Ideals In Prime Rings, Mahmoud El-Soufi, Ahmed Aboubakr

Turkish Journal of Mathematics

Let R be a 2-torsion free prime ring with center Z(R), J be a nonzero Jordan ideal also a subring of R, and F be a generalized derivation with associated derivation d. In the present paper, we shall show that J\subseteq Z(R) if any one of the following properties holds: (i) [F(u), u]\in Z(R), (ii) F(u)u = ud(u), (iii) d(u^2)=2F(u)u, (iv) F(u^2)-2uF(u) = d(u^2)-2ud(u), (v) F^2(u)+3d^2(u)=2Fd(u)+2dF(u), (vi) F(u^2) = 2uF(u) for all u \in J.


On Nr^*-Subgroups Of Finite Groups, Xianggui Zhong Jan 2014

On Nr^*-Subgroups Of Finite Groups, Xianggui Zhong

Turkish Journal of Mathematics

Let G be a finite group and let H be a subgroup of G. H is said to be an NR^*-subgroup of G if there exists a normal subgroup T of G such that G = HT and if whenever K \lhd H and g \in G, then K^g \cap H \cap T\leq K. A number of new characterizations of a group G are given, under the assumption that all Sylow subgroups of certain subgroups of G are NR^*-subgroups.


Hölder Regularity For Weak Solutions Of Diagonal Divergence Quasilinear Degenerate Elliptic Systems, Yan Dong, Xuewei Cui Jan 2014

Hölder Regularity For Weak Solutions Of Diagonal Divergence Quasilinear Degenerate Elliptic Systems, Yan Dong, Xuewei Cui

Turkish Journal of Mathematics

In this paper, we establish Hölder regularity for weak solutions of a class of diagonal divergence quasilinear degenerate elliptic systems of Hörmander's vector fields when the coefficients belong to the class of VMO_X functions with respect to x and uniformly with respect to u, and the lower order terms satisfy a natural growth condition.


Asymptotic Analysis Of The 2-Dimensional Soliton Solutions For The Nizhnik--Veselov--Novikov Equations, Meti̇n Ünal Jan 2014

Asymptotic Analysis Of The 2-Dimensional Soliton Solutions For The Nizhnik--Veselov--Novikov Equations, Meti̇n Ünal

Turkish Journal of Mathematics

In this paper we present a direct approach to determining a class of solutions, the asymptotic analysis of the dromion solutions, and their asymptotic properties of the Nizhnik--Veselov--Novikov equations by means of Pfaffians. The form of the solution obtained allows a detailed asymptotic analysis of the dromion solutions and compact expression for the phase shifts and changes of amplitude as a result of interaction of the dromions to be determined.


Pullback Diagram Of H^*-Algebras, Mahnaz Khanehgir, Maryam Amyari, Marzieh Moradian Khibary Jan 2014

Pullback Diagram Of H^*-Algebras, Mahnaz Khanehgir, Maryam Amyari, Marzieh Moradian Khibary

Turkish Journal of Mathematics

In this paper we obtain some properties for the pullback diagram of H^*-algebras. More precisely, we prove that the commutative diagram of H^*-algebras and morphisms A_1 @>\varphi_1>> B_1 @VV\psi_1V @VV\psi_2V A_2 @>\varphi_2>> B_2 is pullback and \psi_1 is an injection if and only if \psi_1 is a surjection, \psi_2 is an injection, and \ker \varphi_1 \cap \ker \psi_1 = \{0\}.


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.


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.


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.


Counting Pseudo-Anosov Mapping Classes On The 3-Punctured Projective Plane, Blazej Szepietowski Jan 2014

Counting Pseudo-Anosov Mapping Classes On The 3-Punctured Projective Plane, Blazej Szepietowski

Turkish Journal of Mathematics

We prove that in the pure mapping class group of the 3-punctured projective plane equipped with the word metric induced by certain generating set, the ratio of the number of pseudo-Anosov elements to the number of all elements in a ball centered at the identity tends to one, as the radius of the ball tends to infinity. We also compute growth functions of the sets of reducible and pseudo-Anosov elements.


On Minimal Poincaré 4-Complexes, Alberto Cavicchioli, Friedrich Hegenbarth, Dusan Repovs Jan 2014

On Minimal Poincaré 4-Complexes, Alberto Cavicchioli, Friedrich Hegenbarth, Dusan Repovs

Turkish Journal of Mathematics

We consider 2 types of minimal Poincaré 4-complexes. One is defined with respect to the degree 1-map order. This idea was already present in our previous papers, and more systematically studied later by Hillman. The second type of minimal Poincaré 4-complexes was introduced by Hambleton, Kreck, and Teichner. It is not based on an order relation. In the present paper we study existence and uniqueness questions.


Regular Poles For The P-Adic Group Gsp_4, Yusuf Danişman Jan 2014

Regular Poles For The P-Adic Group Gsp_4, Yusuf Danişman

Turkish Journal of Mathematics

We compute the regular poles of the L-factors of the admissible and irreducible representations of the group GSp_4, which admit a nonsplit Bessel functional and have a Jacquet module length of at most 2 with respect to the unipotent radical of the Siegel parabolic, over a non-Archimedean local field of odd characteristic. We also compute the L-factors of the generic representations of GSp_4.


On Density Theorems For Rings Of Krull Type With Zero Divisors, Başak Ay Saylam Jan 2014

On Density Theorems For Rings Of Krull Type With Zero Divisors, Başak Ay Saylam

Turkish Journal of Mathematics

Let R be a commutative ring and I(R) denote the multiplicative group of all invertible fractional ideals of R, ordered by A \leqslant B if and only if B \subseteq A. If R is a Marot ring of Krull type, then R_{(P_i)}, where {P_i}_{i \in I} are a collection of prime regular ideals of R, is a valuation ring and R = \bigcap R_{(P_i)}. We denote by G_i the value group of the valuation associated with R_{(P_i)}. We prove that there is an order homomorphism from I(R) into the cardinal direct sum \coprod_{i \in I} G_i and we investigate the …


Generalized Hypercenter Of A Finite Group, Mohamed Ezzat Mohamed, Mohammed Mosa Alshomrani Jan 2014

Generalized Hypercenter Of A Finite Group, Mohamed Ezzat Mohamed, Mohammed Mosa Alshomrani

Turkish Journal of Mathematics

Let G be a finite group. In this paper, we introduce the concept of super generalized supersolvably embedded subgroup of a group G and give a new characterization of the generalized hypercenter of G.


On The Size Of The Third Homotopy Group Of The Suspension Of An Eilenberg--Maclane Space, Peyman Niroomand, Francesco Russo Jan 2014

On The Size Of The Third Homotopy Group Of The Suspension Of An Eilenberg--Maclane Space, Peyman Niroomand, Francesco Russo

Turkish Journal of Mathematics

The nonabelian tensor square G \otimes G of a group G of G = p^n and G' = p^m (p prime and n,m \ge 1) satisfies a classic bound of the form G \otimes G \le p^{n(n-m)}. This allows us to give an upper bound for the order of the third homotopy group \pi_3(SK(G,1)) of the suspension of an Eilenberg--MacLane space K(G,1), because \pi_3(K(G,1)) is isomorphic to the kernel of \kappa : x \otimes y \in G \otimes G \mapsto [x,y] \in G'. We prove that G \otimes G \le p^{(n-1)(n-m)+2}, sharpening not only G \otimes G \le p^{n(n-m)} but …


Existence, Global Nonexistence, And Asymptotic Behavior Of Solutions For The Cauchy Problem Of A Multidimensional Generalized Damped Boussinesq-Type Equation, Erhan Pi̇şki̇n, Necat Polat Jan 2014

Existence, Global Nonexistence, And Asymptotic Behavior Of Solutions For The Cauchy Problem Of A Multidimensional Generalized Damped Boussinesq-Type Equation, Erhan Pi̇şki̇n, Necat Polat

Turkish Journal of Mathematics

We consider the existence, both locally and globally in time, the global nonexistence, and the asymptotic behavior of solutions for the Cauchy problem of a multidimensional generalized Boussinesq-type equation with a damping term.


Half-Lightlike Submanifolds With Planar Normal Sections In R_2^4, Feyza Esra Erdoğan, Rifat Güneş, Bayram Şahi̇n Jan 2014

Half-Lightlike Submanifolds With Planar Normal Sections In R_2^4, Feyza Esra Erdoğan, Rifat Güneş, Bayram Şahi̇n

Turkish Journal of Mathematics

We investigate half-lightlike submanifolds with planar normal sections of 4-dimensional pseudo-Euclidean space. We obtain necessary and sufficient conditions for a half-lightlike submanifold of R_2^4 such that it has degenerate or nondegenerate planar normal sections.