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Full-Text Articles in Physical Sciences and Mathematics

Notes On Magnetic Curves In 3d Semi-Riemannian Manifolds, Zehra Özdemi̇r, İsmai̇l Gök, Yusuf Yayli, Fai̇k Nejat Ekmekci̇ Jan 2015

Notes On Magnetic Curves In 3d Semi-Riemannian Manifolds, Zehra Özdemi̇r, İsmai̇l Gök, Yusuf Yayli, Fai̇k Nejat Ekmekci̇

Turkish Journal of Mathematics

A magnetic field is defined by the property that its divergence is zero in three-dimensional semi-Riemannian manifolds. Each magnetic field generates a magnetic flow whose trajectories are curves $\gamma $, called magnetic curves. In this paper, we investigate the effect of magnetic fields on the moving particle trajectories by variational approach to the magnetic flow associated with the Killing magnetic field on three-dimensional semi-Riemannian manifolds. We then investigate the trajectories of these magnetic fields and give some characterizations and examples of these curves.


Stability In A Job Market With Linearly Increasing Valuations And Quota System, Yasir Ali Jan 2015

Stability In A Job Market With Linearly Increasing Valuations And Quota System, Yasir Ali

Turkish Journal of Mathematics

We consider a job market in which preferences of players are represented by linearly increasing valuations. The set of players is divided into two disjoint subsets: a set of workers and a set of firms. The set of workers is further divided into subsets, which represent different categories or classes in everyday life. We consider that firms have vacant posts for all such categories. Each worker wants a job for a category to which he/she belongs. Firms have freedom to hire more than one worker from any category. A worker can work in only one category for at most one …


Invariant Distributions And Holomorphic Vector Fields In Paracontact Geometry, Mircea Crasmareanu, Laurian Ioan Piscoran Jan 2015

Invariant Distributions And Holomorphic Vector Fields In Paracontact Geometry, Mircea Crasmareanu, Laurian Ioan Piscoran

Turkish Journal of Mathematics

Having as a model the metric contact case of V. Brînzănescu; R. Slobodeanu, we study two similar subjects in the paracontact (metric) geometry: a) distributions that are invariant with respect to the structure endomorphism $\varphi $; b) the class of vector fields of holomorphic type. As examples we consider both the $3$-dimensional case and the general dimensional case through a Heisenberg-type structure inspired also by contact geometry.


Stability Of Compact Ricci Solitons Under Ricci Flow, Mina Vaghef, Asadollah Razavi Jan 2015

Stability Of Compact Ricci Solitons Under Ricci Flow, Mina Vaghef, Asadollah Razavi

Turkish Journal of Mathematics

In this paper we establish stability results for Ricci solitons under the Ricci flow, i.e. small perturbations of the Ricci soliton result in small variations in the solution under Ricci flow.


A Note On M-Embedded Subgroups Of Finite Groups, Juping Tang, Long Miao Jan 2015

A Note On M-Embedded Subgroups Of Finite Groups, Juping Tang, Long Miao

Turkish Journal of Mathematics

Let $A$ be a subgroup of $G$. $A$ is m-embedded in $G$ if $G$ has a subnormal subgroup $T$ and a $\{1\leq G\}$-embedded subgroup $C$ such that $G=AT$ and $T\cap A\leq C\leq A$. In this paper, we study the structure of finite groups by using m-embedded subgroups and obtain some new results about $p$-supersolvability and $p$-nilpotency of finite groups. \vs{-1mm}


Approximate Duals And Nearly Parseval Frames, Morteza Mirzaee Azandaryani Jan 2015

Approximate Duals And Nearly Parseval Frames, Morteza Mirzaee Azandaryani

Turkish Journal of Mathematics

In this paper we introduce approximate duality of g-frames in Hilbert $C^\ast$-modules and we show that approximate duals of g-frames in Hilbert $C^\ast$-modules share many useful properties with those in Hilbert spaces. Moreover, we obtain some new results for approximate duality of frames and g-frames in Hilbert spaces; in particular, we consider approximate duals of $\varepsilon$-nearly Parseval and $\varepsilon$-close frames.


Some Identities For The Glasser Transform And Their Applications, Faruk Uçar Jan 2015

Some Identities For The Glasser Transform And Their Applications, Faruk Uçar

Turkish Journal of Mathematics

In the present paper we consider a new integral transform, denoted by $\mathcal{G}_{\nu}$, which may be regarded as a generalization of the well-known transform due to Glasser. Many identities involving this transform are given. By making use of these identities, a number of new Parseval--Goldstein type identities are obtained for these and many other well-known integral transforms. The identities proven in this paper are shown to give rise to useful corollaries for evaluating infinite integrals of special functions. Some examples are also given as illustrations of the results presented here.


Existence Of Solutions For A First-Order Nonlocal Boundary Value Problem With Changing-Sign Nonlinearity, Erbi̇l Çeti̇n, Fatma Serap Topal Jan 2015

Existence Of Solutions For A First-Order Nonlocal Boundary Value Problem With Changing-Sign Nonlinearity, Erbi̇l Çeti̇n, Fatma Serap Topal

Turkish Journal of Mathematics

This work is concerned with the existence of positive solutions to a nonlinear nonlocal first-order multipoint problem. Here the nonlinearity is allowed to take on negative values, not only positive values.


On Certain Minimal Non-$\Mathfrak{Y}$-Groups For Some Classes $\Mathfrak{Y}$, Ahmet Arikan, Selami̇ Ercan Jan 2015

On Certain Minimal Non-$\Mathfrak{Y}$-Groups For Some Classes $\Mathfrak{Y}$, Ahmet Arikan, Selami̇ Ercan

Turkish Journal of Mathematics

Let $\{\theta_n\}_{n=1}^\infty$ be a sequence of words. If there exists a positive integer $n$ such that $\theta_m(G)=1$ for every $m\geq n$, then we say that $G$ satisfies (*) and denote the class of all groups satisfying (*) by $\mathfrak{X}_{\{\theta_n\}_{n=1}^\infty}$. If for every proper subgroup $K$ of $G$, $K\in \mathfrak{X}_{\{\theta_n\}_{n=1}^\infty}$ but $G\notin\mathfrak{X}_{\{\theta_n\}_{n=1}^\infty}$, then we call $G$ a minimal non-$\mathfrak{X}_{\{\theta_n\}_{n=1}^\infty}$-group. Assume that $G$ is an infinite locally finite group with trivial center and $\theta_i(G)=G$ for all $i\geq 1$. In this case we mainly prove that there exists a positive integer $t$ such that for every proper normal subgroup $N$ of $G$, either …


The Prime Tournaments $T$ With $\Mid\! W_{5}(T) \!\Mid = \Mid\! T \!\Mid -2$, Houmem Belkhechine, Imed Boudabbous, Kaouthar Hzami Jan 2015

The Prime Tournaments $T$ With $\Mid\! W_{5}(T) \!\Mid = \Mid\! T \!\Mid -2$, Houmem Belkhechine, Imed Boudabbous, Kaouthar Hzami

Turkish Journal of Mathematics

We consider a tournament $T=(V, A)$. For $X\subseteq V$, the subtournament of $T$ induced by $X$ is $T[X] = (X, A \cap (X \times X))$. A module of $T$ is a subset $X$ of $V$ such that for $a, b\in X$ and $ x\in V\setminus X$, $(a,x)\in A$ if and only if $(b,x)\in A$. The trivial modules of $T$ are $\emptyset$, $\{x\}(x\in V)$, and $V$. A tournament is prime if all its modules are trivial. For $n\geq 2$, $W_{2n+1}$ denotes the unique prime tournament defined on $\{0,\dots,2n\}$ such that $W_{2n+1}[\{0,\dots,2n-1\}]$ is the usual total order. Given a prime tournament $T$, …


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".


Uniquely Strongly Clean Triangular Matrices, Huanyin Chen, Orhan Gürgün, Handan Kose Jan 2015

Uniquely Strongly Clean Triangular Matrices, Huanyin Chen, Orhan Gürgün, Handan Kose

Turkish Journal of Mathematics

A ring $R$ is uniquely (strongly) clean provided that for any $a\in R$ there exists a unique idempotent $e\in R$ \big($e\in comm(a)$\big) such that $a-e\in U(R)$. We prove, in this note, that a ring $R$ is uniquely clean and uniquely bleached if and only if $R$ is abelian, ${\mathbb{T}}_{n}(R)$ is uniquely strongly clean for all $n\geq 1$, i.e. every $n\times n$ triangular matrix over $R$ is uniquely strongly clean, if and only if $R$ is abelian, and ${\mathbb{T}}_{n}(R)$ is uniquely strongly clean for some $n\geq 1$. In the commutative case, more explicit results are obtained.


Quadratic Recursive Towers Of Function Fields Over $\Mathbb{F}_2$, Henning Stichtenoth, Seher Tutdere Jan 2015

Quadratic Recursive Towers Of Function Fields Over $\Mathbb{F}_2$, Henning Stichtenoth, Seher Tutdere

Turkish Journal of Mathematics

Let $\FF=(F_n)_{n\geq 0}$ be a quadratic recursive tower of algebraic function fields over the finite field $\F_2$, i.e. $\FF$ is a recursive tower such that $[F_n:F_{n-1}]=2$ for all $n\geq 1$. For any integer $r\geq 1$, let $\beta_r(\FF):=\lim_{n\to \infty} B_r(F_n)/g(F_n)$, where $B_r(F_n)$ is the number of places of degree $r$ and $g(F_n)$ is the genus, respectively, of $F_n/\F_2$. In this paper we give a classification of all rational functions $f(X,Y)\in \F_2(X,Y)$ that may define a quadratic recursive tower $\FF$ over $\F_2$ with at least one positive invariant $\beta_r(\FF)$. Moreover, we estimate $\beta_1(\FF)$ for each such tower.


Split Extension Classifiers In The Category Of Precrossed Modules Of Commutative Algebras, Yaşar Boyaci, Tufan Sai̇t Kuzpinari, Enver Önder Uslu Jan 2015

Split Extension Classifiers In The Category Of Precrossed Modules Of Commutative Algebras, Yaşar Boyaci, Tufan Sai̇t Kuzpinari, Enver Önder Uslu

Turkish Journal of Mathematics

We construct an actor of a precat$^{1}$-algebra and then by using the natural equivalence between the categories of precat$^{1}$-algebras and that of precrossed modules, we construct the split extension classifier of the corresponding precrossed module, which gives rise to the representability of actions in the category of precrossed modules of commutative algebras under certain conditions.


Defect Polynomials And Tutte Polynomials Of Some Asymmetric Graphs, Eunice Mphako-Banda, Toufik Mansour Jan 2015

Defect Polynomials And Tutte Polynomials Of Some Asymmetric Graphs, Eunice Mphako-Banda, Toufik Mansour

Turkish Journal of Mathematics

We give explicit expressions of the Tutte polynomial of asymmetric complete flower graph and asymmetric incomplete flower graph. We then express these Tutte polynomials as generating functions and decode some valuable information about the asymmetric complete flower graph and asymmetric incomplete flower graph. Furthermore, we convert the Tutte polynomials into coboundary polynomials and give explicit expressions of the $k$-defect polynomials of these structures. Finally, we conclude that nonisomorphic graphs in this class have the same Tutte polynomials, the same chromatic polynomials, and the same defect polynomials.


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.


Classification Of Metallic Shaped Hypersurfaces In Real Space Forms, Ci̇han Özgür, Ni̇hal Yilmaz Özgür Jan 2015

Classification Of Metallic Shaped Hypersurfaces In Real Space Forms, Ci̇han Özgür, Ni̇hal Yilmaz Özgür

Turkish Journal of Mathematics

We define the notion of a metallic shaped hypersurface and give the full classification of metallic shaped hypersurfaces in real space forms. We deduce that every metallic shaped hypersurface in real space forms is a semisymmetric hypersurface.


Generalized Chebyshev Polynomials Of The Second Kind, Mohammad A. Alqudah Jan 2015

Generalized Chebyshev Polynomials Of The Second Kind, Mohammad A. Alqudah

Turkish Journal of Mathematics

We characterize the generalized Chebyshev polynomials of the second kind (Chebyshev-II), and then we provide a closed form of the generalized Chebyshev-II polynomials using the Bernstein basis. These polynomials can be used to describe the approximation of continuous functions by Chebyshev interpolation and Chebyshev series and how to efficiently compute such approximations. We conclude the paper with some results concerning integrals of the generalized Chebyshev-II and Bernstein polynomials.


Existence Of Unique Solution To Switchedfractional Differential Equations With $P$-Laplacian Operator, Xiufeng Guo Jan 2015

Existence Of Unique Solution To Switchedfractional Differential Equations With $P$-Laplacian Operator, Xiufeng Guo

Turkish Journal of Mathematics

In this paper, we study a class of nonlinear switched systems of fractional order with $p$-Laplacian operator. By applying a fixed point theorem for a concave operator on a cone, we obtain the existence and uniqueness of a positive solution for an integral boundary value problem with switched nonlinearity under some suitable assumptions. An illustrative example is included to show that the obtained results are effective.


Special Proper Pointwise Slant Surfaces Of A Locally Product Riemannian Manifold, Mehmet Gülbahar, Erol Kiliç, Semra Saraçoğlu Çeli̇k Jan 2015

Special Proper Pointwise Slant Surfaces Of A Locally Product Riemannian Manifold, Mehmet Gülbahar, Erol Kiliç, Semra Saraçoğlu Çeli̇k

Turkish Journal of Mathematics

The structure of pointwise slant submanifolds in an almost product Riemannian manifold is investigated and the special proper pointwise slant surfaces of a locally product manifold are introduced. A relation involving the squared mean curvature and the Gauss curvature of pointwise slant surface of a locally product manifold is proved. Two examples of proper pointwise slant surfaces of a locally product manifold, one of which is special and the other one is not special, are given.


Optimality Criteria For Sum Of Fractional Multiobjective Optimization Problem With Generalized Invexity, Deepak Bhati, Pitam Singh Jan 2015

Optimality Criteria For Sum Of Fractional Multiobjective Optimization Problem With Generalized Invexity, Deepak Bhati, Pitam Singh

Turkish Journal of Mathematics

The sum of a fractional program is a nonconvex optimization problem in the field of fractional programming and it is difficult to solve. The development of research is restricted to single objective sums of fractional problems only. The branch and bound methods/algorithms are developed in the literature for this problem as a single objective problem. The theoretical and algorithmic development for sums of fractional programming problems is restricted to single objective problems. In this paper, some new optimality conditions are proposed for the sum of a fractional multiobjective optimization problem with generalized invexity. The optimality conditions are obtained by using …


Some Properties Of A Class Of Analytic Functions Defined Bygeneralized Struve Functions, Mohsan Raza, Ni̇hat Yağmur Jan 2015

Some Properties Of A Class Of Analytic Functions Defined Bygeneralized Struve Functions, Mohsan Raza, Ni̇hat Yağmur

Turkish Journal of Mathematics

The aim of this paper is to define \ a new operator by using the generalized Struve functions $\sum\limits_{n=0}^{\infty }\frac{\left( -c/4\right) ^{n}}{\left( 3/2\right) _{n}\left( k\right) _{n}}z^{n+1}$ with $% k$ $=p+$ $\left( b+2\right) /2\neq 0,-1,-2,\ldots $ and $b,c,k\in \mathbb{C} $. By using this operator we define a subclass of analytic functions. We discuss some properties of this class such as inclusion problems, radius problems, and some other interesting properties related to this operator.


On The Classification Of Almost Null Rings, Ryszard Andruszkiewicz, Karol Pryszczepko Jan 2015

On The Classification Of Almost Null Rings, Ryszard Andruszkiewicz, Karol Pryszczepko

Turkish Journal of Mathematics

An almost null ring is a ring $R$ in which for all $a,b\in R$, $a^3=0$, $Ma^2=0$ for some square-free integer $M$ that depends on $a$ and $ab= ka^{2}=l b^{2}$ for some integers $k,l$. This paper is devoted to the classification of the almost null rings.


On Metallic Riemannian Structures, Aydin Gezer, Çağri Karaman Jan 2015

On Metallic Riemannian Structures, Aydin Gezer, Çağri Karaman

Turkish Journal of Mathematics

The paper is devoted to the study of metallic Riemannian structures. An integrability condition and curvature properties for these structures by means of a $\Phi $-operator applied to pure tensor fields are presented. Examples of these structures are also given.


Magnetic Curves On Flat Para-K\"Ahler Manifolds, Mohamed Jleli, Marian Ioan Munteanu Jan 2015

Magnetic Curves On Flat Para-K\"Ahler Manifolds, Mohamed Jleli, Marian Ioan Munteanu

Turkish Journal of Mathematics

In this paper we prove that spacelike and timelike magnetic trajectories corresponding to the para-K\"ahler 2-form on a para-K\"ahler manifold $(M,\p,g)$ are circles on $M$. We then classify all para-K\"ahler magnetic curves in pseudo-Euclidean spaces ${\mathbb{E}}^{2n}_n$.


Equivalencies Between Beta-Shifts And S-Gap Shifts, Dawoud Ahmadi Dastjerdi, Somayyeh Jangjoo Shaldehi Jan 2015

Equivalencies Between Beta-Shifts And S-Gap Shifts, Dawoud Ahmadi Dastjerdi, Somayyeh Jangjoo Shaldehi

Turkish Journal of Mathematics

Let X_{\beta} be a \beta -shift for \beta \in (1, 2] and X(S) a S-gap shift for S\subseteq N \cup {0}. We show that if X_\beta is SFT (resp. sofic), then there is a unique S-gap shift conjugate (resp. right-resolving almost conjugate) to this X_\beta, and if X_\beta is not SFT, then no S-gap shift is conjugate to X_\beta. For any synchronized X_{\beta} , an X(S) exists such that X_{\beta} and X(S) have a common synchronized 1-1 a.e. extension. For a nonsynchronized X_\beta, this common extension is just an almost Markov synchronized system with entropy preserving maps. We then compute …


Some Concrete Operators And Their Properties, Mehmet Gürdal, Mubariz T. Garayev, Suna Saltan Jan 2015

Some Concrete Operators And Their Properties, Mehmet Gürdal, Mubariz T. Garayev, Suna Saltan

Turkish Journal of Mathematics

We consider integration and double integration operators, the Hardy operator, and multiplication and composition operators on Lebesgue space $L_{p}\left[ 0,1\right] $ and Sobolev spaces $W_{p}^{\left( n\right) }\left[ 0,1\right] $ and $W_{p}^{\left( n\right) }\left( \left[ 0,1\right] \times\left[ 0,1\right] \right) ,$ and we study their properties. In particular, we calculate norm and spectral multiplicity of the Hardy operator and some multiplication operators, investigate its extended eigenvectors, characterize some composition operators in terms of the extended eigenvectors of the Hardy operator, and calculate the numerical radius of the integration operator on the real $L_{2}\left[ 0,1\right] $ space. The main method for our investigation …


On Zeros Of Certain Dirichlet Polynomials, Kajtaz H. Bllaca Jan 2015

On Zeros Of Certain Dirichlet Polynomials, Kajtaz H. Bllaca

Turkish Journal of Mathematics

In this article we establish the zero-free region of certain Dirichlet polynomials $L_{F, X}$ arising in approximate functional equation for functions in the Selberg class and we prove an asymptotic formula for the number of zeros of $L_{F, X}$.


Bifurcation And Dynamics Of A Normal Form Map, Reza Khoshsiar Ghaziani Jan 2015

Bifurcation And Dynamics Of A Normal Form Map, Reza Khoshsiar Ghaziani

Turkish Journal of Mathematics

This paper investigates the dynamics and stability properties of a so-called planar truncated normal form map. This kind of map is widely used in the applied context, especially in normal form coefficients of n-dimensional maps. We determine analytically the border collision bifurcation curves that characterize the dynamic behaviors of the system. We first analyze stability of the fixed points and the existence of local bifurcations. Our analysis shows the presence of a rich variety of local bifurcations, namely stable fixed points, periodic cycles, quasiperiodic cycles that are constraints to stable attractors called invariant closed curves, and chaos, where dynamics of …


On Ampleness And Pseudo-Anosov Homeomorphisms In The Free Group, Rizos Sklinos Jan 2015

On Ampleness And Pseudo-Anosov Homeomorphisms In The Free Group, Rizos Sklinos

Turkish Journal of Mathematics

We use pseudo-Anosov homeomorphisms of surfaces in order to prove that the first-order theory of non-Abelian free groups, T_{fg}, is n-ample for any n \in \omega. This result adds to the work of Pillay, which proved that T_{fg} is non-CM-trivial. The sequence witnessing ampleness is a sequence of primitive elements in F_{\omega}. Our result provides an alternative proof to the main result of a recent preprint by Ould Houcine and Tent.