Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 751

Full-Text Articles in Physical Sciences and Mathematics

Continuous Dependence Of Solutions To The Strongly Damped Nonlinear Klein-Gordon Equation, Şevket Gür, Mesude Eli̇f Uysal Jan 2018

Continuous Dependence Of Solutions To The Strongly Damped Nonlinear Klein-Gordon Equation, Şevket Gür, Mesude Eli̇f Uysal

Turkish Journal of Mathematics

This article is devoted to the study of the initial-boundary value problem for the strongly damped nonlinear Klein-Gordon equation. It is proved that the solution depends continuously on changes in the damping terms, diffusion, mass, and nonlinearity effect term in the $H^1$ norm.


Reflexivity Of Vector-Valued Köthe-Orlicz Sequence Spaces, Mohamed Ahmed Ould Sidaty Jan 2018

Reflexivity Of Vector-Valued Köthe-Orlicz Sequence Spaces, Mohamed Ahmed Ould Sidaty

Turkish Journal of Mathematics

Let $E$ be a Banach space, $\lambda$ a perfect sequence space, and $M$ an Orlicz function. Denote by $\lambda \left(E, M\right)_{r}$ the space of all weakly $(M, \lambda)$-summable sequences from $E$ that are the limit of their finite sections. In this paper, we describe the continuous linear functionals on $\lambda \left(E, M\right)_{r}$ in terms of strongly $(N, \lambda^{\ast})$-summable sequences in the dual $E^{*}$ of $E$, and then we give a characterization of the reflexivity of $\lambda \left(E, M\right)$ in terms of that of $\lambda$ and of $E$ and the AK-property.


Early Pliocene Molluscs From The Easternmost Mediterranean Region (Se Turkey): Biostratigraphic, Ecostratigraphic, And Palaeobiogeographic Implications, Yeşi̇m Büyükmeri̇ç, Erdoğan Teki̇n, Erdal İbrahi̇m Herece, Koray Sözeri̇, Ni̇hal Akca, Baki̇ Erdoğan Varol Jan 2018

Early Pliocene Molluscs From The Easternmost Mediterranean Region (Se Turkey): Biostratigraphic, Ecostratigraphic, And Palaeobiogeographic Implications, Yeşi̇m Büyükmeri̇ç, Erdoğan Teki̇n, Erdal İbrahi̇m Herece, Koray Sözeri̇, Ni̇hal Akca, Baki̇ Erdoğan Varol

Turkish Journal of Earth Sciences

The mollusc faunas from Pliocene deposits of the Hatay-İskenderun region were investigated at nine localities and complemented with three localities from earlier studies. The Pliocene units were deposited in three adjacent subbasins, Hatay-Samandağ (HS), Altınözü-Babatorun (AB), and İskenderun-Arsuz (İA); the first two are also known as the Hatay Graben. Basin configurations and shape, environmental evolution, and faunal compositions were affected by differential tectonic histories since the Late Miocene. In total 162 species (94 gastropod, 61 bivalve, and 7 scaphopod) are recorded, 80 of which are recorded for the first time from the region. The occurrence of tropical stenohaline benthic taxa …


A Coanalytic Menger Group That Is Not $\Sigma$-Compact, Seçi̇l Tokgöz Jan 2018

A Coanalytic Menger Group That Is Not $\Sigma$-Compact, Seçi̇l Tokgöz

Turkish Journal of Mathematics

Under $V=L$ we construct coanalytic topological subgroups of reals, demonstrating that even for definable groups of reals, selection principles may differ.


On The Unit Index Of Some Real Biquadratic Number Fields, Abdelmalek Azizi, Abdelkader Zekhnini, Mohammed Taous Jan 2018

On The Unit Index Of Some Real Biquadratic Number Fields, Abdelmalek Azizi, Abdelkader Zekhnini, Mohammed Taous

Turkish Journal of Mathematics

Let $p_1\equiv p_2\equiv1 \pmod 4$ be different prime numbers such that $\left(\dfrac{2}{p_2}\right)=\left(\dfrac{p_1}{p_2}\right)=-\left(\dfrac{2}{p_1}\right)=-1$. Put $\kk=\QQ(\sqrt{2p_1p_2})$ and let $\KK$ be a quadratic extension of $\kk$ contained in its absolute genus field $\kk^{(*)}$. Denote by $k_j$, $1\leq j\leq 3$, the three quadratic subfields of $\KK$. Let $E_{\KK}$ (resp. $E_{k_j}$) be the unit group of $\KK$ (resp. $k_j$). The unit index $\left[E_{\KK}: \prod_{j=1}^3E_{k_j}\right]$ is characterized in terms of biquadratic residue symbols between $2$, $p_1$ and $p_2$ or by the capitulation of $\mathfrak{2}$, the prime ideal of $\QQ(\sqrt{2p_1})$ above $2$, in $\KK$. These results are used to describe the $2$-rank of some CM-fields.


Coefficient Estimates For A Class Containing Quasi-Convex Functions, Osman Altintaş, Öznur Özkan Kiliç Jan 2018

Coefficient Estimates For A Class Containing Quasi-Convex Functions, Osman Altintaş, Öznur Özkan Kiliç

Turkish Journal of Mathematics

In the present study, we introduce the classes $\mathcal {Q_{CV}}\left(\mu, A,B \right)$ and $\mathcal{Q_{ST}}\left(\eta, A,B \right)$. Furthermore, we obtain coefficient bounds of these classes.


On The Chebyshev Coefficients For A General Subclass Of Univalentfunctions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz Jan 2018

On The Chebyshev Coefficients For A General Subclass Of Univalentfunctions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz

Turkish Journal of Mathematics

In this work, considering a general subclass of univalent functions and using the Chebyshev polynomials, we obtain coefficient expansions for functions in this class.


Linear Methods Of Summing Fourier Series And Approximation In Weighted Orliczspaces, Sadulla Jafarov Jan 2018

Linear Methods Of Summing Fourier Series And Approximation In Weighted Orliczspaces, Sadulla Jafarov

Turkish Journal of Mathematics

In the present work, we investigate estimates of the deviations of the periodic functions from the linear operators constructed on the basis of its Fourier series in reflexive weighted Orlicz spaces with Muckenhoupt weights. In particular, the orders of approximation of Zygmund and Abel-Poisson means of Fourier trigonometric series were estimated by the $k-th$~modulus of smoothness in reflexive weighted Orlicz spaces with Muckenhoupt weights.


The Diameter Vulnerability Of The Generalized Petersen Graph ${Gp[Tk,K]}$, Gülnaz Boruzanli Eki̇nci̇, John Baptist Gauci Jan 2018

The Diameter Vulnerability Of The Generalized Petersen Graph ${Gp[Tk,K]}$, Gülnaz Boruzanli Eki̇nci̇, John Baptist Gauci

Turkish Journal of Mathematics

The diameter of a graph gives the length of the longest path among all the shortest paths between any two vertices of the graph, and the diameter vulnerability problem measures the change in the diameter upon the deletion of edges. In this paper we determine the diameter vulnerability of the generalized Petersen graph $GP[tk,k]$, for integers $t\geq 2$ and $k\geq 1$, and show that (except for some small cases) the diameter remains unchanged upon the deletion of one edge. This work contributes towards a solution of the well-known $(\Delta, D, D', s)$-problem, which attempts to find large graphs with maximum …


Construction Of The Second Hankel Determinant For A New Subclass Ofbi-Univalent Functions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz Jan 2018

Construction Of The Second Hankel Determinant For A New Subclass Ofbi-Univalent Functions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz

Turkish Journal of Mathematics

In this paper, we will discuss a newly constructed subclass of bi-starlike functions. Furthermore, we establish bounds for the coefficients and get the second Hankel determinant for the class $S_{\Sigma }(\alpha ,\beta ).$


Description Of Invariant Subspaces In Terms Of Berezin Symbols, Suna Saltan Jan 2018

Description Of Invariant Subspaces In Terms Of Berezin Symbols, Suna Saltan

Turkish Journal of Mathematics

We consider the stretching operator $\left( T_{w}f\right) \left( z\right) =f(wz)$ and the multiple shift operator $S^{n}f=z^{n}f$ on the Hardy spaces $% H^{p}(\mathbb{D})$ $\left( 1\leq p


Free Modules And Crossed Modules Of $R$-Algebroids, Osman Avcioğlu, İbrahi̇m İlker Akça Jan 2018

Free Modules And Crossed Modules Of $R$-Algebroids, Osman Avcioğlu, İbrahi̇m İlker Akça

Turkish Journal of Mathematics

In this paper, first, we construct the free modules and precrossed modules of $R$-algebroids. Then we introduce the Peiffer ideal of a precrossed module and use it to construct the free crossed module.


On A New Subclass Of Bi-Univalent Functions Defined By Using Salagean Operator, Bi̇lal Şeker Jan 2018

On A New Subclass Of Bi-Univalent Functions Defined By Using Salagean Operator, Bi̇lal Şeker

Turkish Journal of Mathematics

In this manuscript, by using the Salagean operator, new subclasses of bi-univalent functions in the open unit disk are defined. Moreover, for functions belonging to these new subclasses, upper bounds for the second and third coefficients are found.


Generalization Of The Cayley Transform In 3d Homogeneous Geometries, Zlatko Erjavec Jan 2018

Generalization Of The Cayley Transform In 3d Homogeneous Geometries, Zlatko Erjavec

Turkish Journal of Mathematics

The Cayley transform maps the unit disk onto the upper half-plane, conformally and isometrically. In this paper, we generalize the Cayley transform in three-dimensional homogeneous geometries which are fiber bundles over the hyperbolic plane. Obtained generalizations are isometries between existing models in corresponding homogeneous geometries. Particularly, constructed isometry between two models of { $\widetilde{SL(2,\mathbb{R})}$} geometry is nontrivial and enables comparison and transfer of known and even future results between these two models.


Trigonometric Expressions For Infinite Series Involving Binomial Coefficients, Nadia Li Jan 2018

Trigonometric Expressions For Infinite Series Involving Binomial Coefficients, Nadia Li

Turkish Journal of Mathematics

By means of the hypergeometric series approach, we present a new proof of Sun's conjecture on trigonometric series, which is simpler than the original one due to Sun and Meng. Several further infinite series identities are shown as examples.


When Is A Permutation Of The Set $\Z^N$ (Resp. $\Z_P^N$, $P$ Prime) An Automorphism Of The Group $\Z^N$ (Resp. $\Z_P^N$)?, Ben-Eben De Klerk, Johan H. Meyer Jan 2018

When Is A Permutation Of The Set $\Z^N$ (Resp. $\Z_P^N$, $P$ Prime) An Automorphism Of The Group $\Z^N$ (Resp. $\Z_P^N$)?, Ben-Eben De Klerk, Johan H. Meyer

Turkish Journal of Mathematics

For a given positive integer $n$, the structure, i.e. the number of cycles of various lengths, as well as possible chains, of the automorphisms of the groups $(\Z^n, +)$ and $(\Z_p^n,+)$, \ $p$ prime, is studied. In other words, necessary and sufficient conditions on a bijection $f : A \ra A$, where $ A $ is countably infinite (alternatively, of order $p^n$), are determined so that $A$ can be endowed with a binary operation $*$ such that $(A,*)$ is a group isomorphic to $(\Z^n,+)$ (alternatively, $(\Z_p^n,+)$) and such that $f\in \Aut(A)$.


On The Asymptotic Behavior Of Solution Of Certain Systems Of Volterra Equations, Ewa Schmeidel, Malgorzata Zdanowicz Jan 2018

On The Asymptotic Behavior Of Solution Of Certain Systems Of Volterra Equations, Ewa Schmeidel, Malgorzata Zdanowicz

Turkish Journal of Mathematics

This paper is concerned with the asymptotic property of the solution of a system of the linear Volterra difference equations. The criterion for the existence of a solution of the considered system that is asymptotically equivalent to a given sequence is established. %The results generalize some recent results. The results presented here improve and generalize the results published by Diblik et al. Unlike in those works, here periodicity of the nonhomogeneous term of the equation is not assumed. Examples illustrate the obtained results.


Existence Of Solution For Some Two-Point Boundary Value Fractional Differential Equations, Kenneth Ifeanyi Isife Jan 2018

Existence Of Solution For Some Two-Point Boundary Value Fractional Differential Equations, Kenneth Ifeanyi Isife

Turkish Journal of Mathematics

Using a fixed point theorem, we establish the existence of a solution for a class of boundary value fractional differential equation. Secondly, we will adopt the method of successive approximations to obtain an approximate solution to our problem. Furthermore, using the Laplace transform technique, an explicit solution to a particular case of our problem is obtained. Finally, some examples are given to illustrate our results.


Almost Paracontact Structures Obtained From $G_{2(2)}^*$ Structures, Nüli̇fer Özdemi̇r, Şi̇ri̇n Aktay, Mehmet Solgun Jan 2018

Almost Paracontact Structures Obtained From $G_{2(2)}^*$ Structures, Nüli̇fer Özdemi̇r, Şi̇ri̇n Aktay, Mehmet Solgun

Turkish Journal of Mathematics

In this paper, we construct almost paracontact metric structures by using the fundamental 3-forms of manifolds with $G_{2(2)}^*$ structures. The existence of certain almost paracontact metric structures is investigated due to the properties of the 2-fold vector cross-product. Furthermore, we give some relations between the classes of $G_{2(2)}^*$ structures and almost paracontact metric structures.


On Hochstadt--Lieberman Theorem For Impulsive Sturm-Liouville Problems With Boundary Conditions Polynomially Dependent On The Spectral Parameter, Seyfollah Mosazadeh, Aliasghar Jodayree Akbarfam Jan 2018

On Hochstadt--Lieberman Theorem For Impulsive Sturm-Liouville Problems With Boundary Conditions Polynomially Dependent On The Spectral Parameter, Seyfollah Mosazadeh, Aliasghar Jodayree Akbarfam

Turkish Journal of Mathematics

In the present paper, we consider an inverse problem for the Sturm-Liouville operator with a finite number of discontinuities at interior points and boundary conditions polynomially dependent on the spectral parameter on an arbitrary finite interval, and prove the Hochstadt-Lieberman-type theorem for this problem.


Several Hardy-Type Inequalities With Weights Related To Baouendi--Grushinoperators, Abdullah Yener Jan 2018

Several Hardy-Type Inequalities With Weights Related To Baouendi--Grushinoperators, Abdullah Yener

Turkish Journal of Mathematics

In this paper we shall prove several weighted $L^{p}$ Hardy-type inequalities associated to the Baouendi-Grushin-type operators $\Delta _{\gamma }=\Delta _{x}+\left\vert x\right\vert ^{2\gamma }\Delta _{y},$ where $\Delta _{x}$ and $\Delta _{y}$ are the classical Laplace operators in the variables $x\in \mathbb{R}^{n}$ and $y\in \mathbb{R}^{k},$ respectively, and $\gamma $ is a positive real number.


Linearized Four-Step Implicit Scheme For Nonlinear Parabolic Interface Problems, Matthew Olayiwola Adewole, Victor Folarin Payne Jan 2018

Linearized Four-Step Implicit Scheme For Nonlinear Parabolic Interface Problems, Matthew Olayiwola Adewole, Victor Folarin Payne

Turkish Journal of Mathematics

We present the solution of a second-order nonlinear parabolic interface problem on a quasiuniform triangular finite element with a linearized four-step implicit scheme used for the time discretization. The convergence of the scheme in $L^2$-norm is established under certain regularity assumptions using interpolation and elliptic projection operators. A numerical experiment is presented to support the theoretical result. It is assumed that the interface cannot be fitted exactly.


Some Characterizations Of Right $C$-Regularity And $(B,C)$-Inverse, Ruju Zhao, Hua Yao, Long Wang, Junchao Wei Jan 2018

Some Characterizations Of Right $C$-Regularity And $(B,C)$-Inverse, Ruju Zhao, Hua Yao, Long Wang, Junchao Wei

Turkish Journal of Mathematics

Let $R$ be a ring and $a,b,c\in R$. We give a novel characterization of group inverses (resp. EP elements) by the properties of right (resp. left ) $c$-regular inverses of $a$ and discuss the relation among the strongly left $(b,c)$-invertibility of $a$, the right $ca$-regularity of $b$, and the $(b,c)$-invertibility of $a$. Finally, we investigate the sufficient and necessary condition for a ring to be a strongly left min-Abel ring by means of the $(b,c)$-inverse of $a$.


On The Solution Of An Inverse Sturm-Liouville Problem With A Delay And Eigenparameter-Dependent Boundary Conditions, Seyfollah Mosazadeh Jan 2018

On The Solution Of An Inverse Sturm-Liouville Problem With A Delay And Eigenparameter-Dependent Boundary Conditions, Seyfollah Mosazadeh

Turkish Journal of Mathematics

In this paper, a boundary value problem consisting of a delay differential equation of the Sturm-Liouville type with eigenparameter-dependent boundary conditions is investigated. The asymptotic behavior of eigenvalues is studied and the parameter of delay is determined by eigenvalues. Then we obtain the connection between the potential function and the canonical form of the characteristic function.


Radii Of Uniform Convexity Of Some Special Functions, İbrahi̇m Aktaş, Evri̇m Toklu, Hali̇t Orhan Jan 2018

Radii Of Uniform Convexity Of Some Special Functions, İbrahi̇m Aktaş, Evri̇m Toklu, Hali̇t Orhan

Turkish Journal of Mathematics

In this investigation our main aim is to determine the radii of uniform convexity of selected normalized $ q $-Bessel and Wright functions. Here we consider six different normalized forms of $ q $-Bessel functions and we apply three different kinds of the normalization of the Wright function. We also show that the obtained radii are the smallest positive roots of some functional equations.


Generalized Metric $N$-Leibniz Algebras And Generalized Orthogonal Representation Of Metric Lie Algebras, Rong Tang, Lina Song Jan 2018

Generalized Metric $N$-Leibniz Algebras And Generalized Orthogonal Representation Of Metric Lie Algebras, Rong Tang, Lina Song

Turkish Journal of Mathematics

We introduce the notion of a generalized metric $n$-Leibniz algebra and show that there is a one-to-one correspondence between generalized metric $n$-Leibniz algebras and faithful generalized orthogonal representations of metric Lie algebras (called Lie triple datas). We further show that there is also a one-to-one correspondence between generalized orthogonal derivations (resp. generalized orthogonal automorphisms) on generalized metric $n$-Leibniz algebras and Lie triple data.


Closed Range Properties Of Li-Steviç Integral-Type Operators Between Bloch-Type Spaces And Their Essential Norms, Maryam Mohammadi Pirasteh, Nasrin Eghbali, Amir Hossein Sanatpour Jan 2018

Closed Range Properties Of Li-Steviç Integral-Type Operators Between Bloch-Type Spaces And Their Essential Norms, Maryam Mohammadi Pirasteh, Nasrin Eghbali, Amir Hossein Sanatpour

Turkish Journal of Mathematics

We investigate closed range properties of certain integral-type operators introduced by Li and Steviç. The operators are considered between Bloch-type spaces. We also give the essential norm of such operators. Our results are given in a general setting and we also give the essential norm of Li-Steviç integral-type operators between other well-known spaces of analytic functions.


Curves Whose Pseudo Spherical Indicatrices Are Elastic, Ahmet Yücesan, Gözde Özkan Tükel, Tunahan Turhan Jan 2018

Curves Whose Pseudo Spherical Indicatrices Are Elastic, Ahmet Yücesan, Gözde Özkan Tükel, Tunahan Turhan

Turkish Journal of Mathematics

The pseudo spherical indicatrix of a curve in Minkowski $3$-space emerges as three types: the pseudo spherical tangent indicatrix, principal normal indicatrix, and binormal indicatrix of the curve. The pseudo spherical tangent, principal normal, and binormal indicatrix of a regular curve may be positioned on De Sitter $2$-space (pseudo sphere), pseudo hyperbolic 2-space, and two-dimensional null cone in terms of causal character of the curve. In this paper, we separately derive Euler-Lagrange equations of all pseudo spherical indicatrix elastic curves in terms of the causal character of a curve in Minkowski $3$-space. Then we give some results of solutions of …


Conditional Expectation Type Operators And Modular Inequalities, Dah-Chin Luor Jan 2018

Conditional Expectation Type Operators And Modular Inequalities, Dah-Chin Luor

Turkish Journal of Mathematics

In this paper we discuss the connection between conditional expectation type operators and integral operators. A variant of Schur's lemma is established and we obtain modular inequalities for a class of conditional expectation type operators.


Transversal Lightlikesubmanifolds Of Metallic Semi-Riemannian Manifolds, Feyza Esra Erdoğan Jan 2018

Transversal Lightlikesubmanifolds Of Metallic Semi-Riemannian Manifolds, Feyza Esra Erdoğan

Turkish Journal of Mathematics

The main purpose of the present paper is to study the geometry of transversal lightlike submanifolds and radical transversal lightlike submanifolds of metallic semi-Riemannian manifolds. We investigate the geometry of distributions and obtain necessary and sufficient conditions for the induced connection on these manifolds to be a metric connection. We also obtain characterization of transversal lightlike submanifolds of metallic semi-Riemannian manifolds. Finally, we give two examples.