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

Mathematics Commons™

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

Articles 511 - 540 of 2595

Full-Text Articles in Mathematics

Formulas For Special Numbers And Polynomials Derived From Functional Equations Of Their Generating Functions, Nesli̇han Kilar Jan 2022

Formulas For Special Numbers And Polynomials Derived From Functional Equations Of Their Generating Functions, Nesli̇han Kilar

Turkish Journal of Mathematics

The main purpose of this paper is to investigate various formulas, identities and relations involving Apostol type numbers and parametric type polynomials. By using generating functions and their functional equations, we give many relations among the certain family of combinatorial numbers, the Vieta polynomials, the two-parametric types of the Apostol-Euler polynomials, the Apostol-Bernoulli polynomials, the Apostol-Genocchi polynomials, the Fibonacci and Lucas numbers, the Chebyshev polynomials, and other special numbers and polynomials. Moreover, we give some formulas related to trigonometric functions, special numbers and special polynomials. Finally, some remarks and observations on the results of this paper are given.


Integer-Valued Polynomials Satisfying The Lucas Property, Rattiya Meesa, Vichian Laohakosol, Tuangrat Chaichana Jan 2021

Integer-Valued Polynomials Satisfying The Lucas Property, Rattiya Meesa, Vichian Laohakosol, Tuangrat Chaichana

Turkish Journal of Mathematics

The classical theorem of Lucas states that the binomial polynomials, which form a basis for integer-valued polynomials, satisfy a congruence relation related to their integer parameters. We consider here three problems connected with this result in the setting of discrete valued structures. The first problem asks for the shapes of Lagrange-type interpolation polynomials which constitute a basis for integer-valued polynomials and satisfy the Lucas property; the result so obtained extends a 2001 result of Boulanger and Chabert. For the second problem, we show that the Carlitz polynomials, which form a basis for integer-valued polynomials in a function field, satisfy the …


Liftings And Covering Morphisms Of Crossed Modules In Group-Groupoids, Serap Demi̇r Karakaş, Osman Mucuk Jan 2021

Liftings And Covering Morphisms Of Crossed Modules In Group-Groupoids, Serap Demi̇r Karakaş, Osman Mucuk

Turkish Journal of Mathematics

In this work we introduce lifting and covering of a crossed module in the category of group-groupoids; and then we prove the categorical equivalence of horizontal actions of a double group-groupoid and lifting crossed modules of corresponding crossed module in group-groupoids. These allow us to produce more examples of double group-groupoids.


A Short Note On Generic Initial Ideals, Beki̇r Daniş Jan 2021

A Short Note On Generic Initial Ideals, Beki̇r Daniş

Turkish Journal of Mathematics

The definition of a generic initial ideal includes the assumption $x_1>x_2> \cdots >x_n$. A natural question is how generic initial ideals change when we permute the variables. In the article [1, §2], it is shown that the generic initial ideals are permuted in the same way when the variables in the monomial order are permuted. We give a different proof of this theorem. Along the way, we study the Zariski open sets which play an essential role in the definition of a generic initial ideal and also prove a result on how the Zariski open set changes after a …


On The Analytical Development Of Incomplete Riemann-Liouville Fractional Calculus, Arran Fernandez, Ceren Ustaoğlu, Mehmet Ali̇ Özarslan Jan 2021

On The Analytical Development Of Incomplete Riemann-Liouville Fractional Calculus, Arran Fernandez, Ceren Ustaoğlu, Mehmet Ali̇ Özarslan

Turkish Journal of Mathematics

The theoretical development of fractional calculus includes the formulation of different definitions, the extension of properties from standard calculus, and the application of fractional operators to special functions. In two recent papers, incomplete versions of classical fractional operators were formulated in connection with special functions. Here, we develop the theory of incomplete fractional calculus more deeply, investigating further properties of these operators and answering some fundamental questions about how they work. By considering appropriate function spaces, we discover that incomplete fractional calculus may be used to analyse a wider class of functions than classical fractional calculus can consider. By using …


Certain Subclasses Of Spirallike Univalent Functions Related To Poisson Distribution Series, Lakshminarayanan Vanitha, Chellakutti Ramachandran, Teodor Bulboaca Jan 2021

Certain Subclasses Of Spirallike Univalent Functions Related To Poisson Distribution Series, Lakshminarayanan Vanitha, Chellakutti Ramachandran, Teodor Bulboaca

Turkish Journal of Mathematics

The aim of the present study is to find the essential properties for some subclasses of analytic functions which are related to Poisson distribution that are member of the classes of spiral-like univalent functions. Further, we studied inclusion relations for such subclasses, and also we determined some properties of an integral operator related to Poisson distribution series. Several corollaries and consequences of the main results are also considered.


Extensions Of The Matrix-Valued$\ Q-$Sturm-Liouville Operators, Bi̇lender Paşaoğlu, Hüseyi̇n Tuna Jan 2021

Extensions Of The Matrix-Valued$\ Q-$Sturm-Liouville Operators, Bi̇lender Paşaoğlu, Hüseyi̇n Tuna

Turkish Journal of Mathematics

In this paper, we investigate the matrix-valued$\ q-$Sturm--Liouville problems. We establish an existence and uniqueness result. Later, we introduce the corresponding maximal and minimal operators for this system. Moreover, we give a criterion under which these operators are self-adjoint. Finally, we characterize extensions (maximal dissipative, maximal accumulative, and self-adjoint) of the minimal symmetric operator.


Statistically Multiplicative Convergence On Locally Solid Riesz Algebras, Abdullah Aydin, Mi̇kai̇l Et Jan 2021

Statistically Multiplicative Convergence On Locally Solid Riesz Algebras, Abdullah Aydin, Mi̇kai̇l Et

Turkish Journal of Mathematics

In this paper, we introduce the statistically multiplicative convergent sequences in locally solid Riesz algebras with respect to algebra multiplication and solid topology. We study this concept and the notion of $st_m$-bounded sequences, and also, we prove some relations between this convergence and the other convergences such as the order convergence and the statistical convergence in topological spaces. Also, we give some results related to semiprime $f$-algebras.


Generalized Stevi\'C-Sharma Type Operators From Hardy Spaces Into $N$Th Weighted Type Spaces, Ebrahim Abbasi, Yongmin Liu, Mostafa Hassanlou Jan 2021

Generalized Stevi\'C-Sharma Type Operators From Hardy Spaces Into $N$Th Weighted Type Spaces, Ebrahim Abbasi, Yongmin Liu, Mostafa Hassanlou

Turkish Journal of Mathematics

In this paper, some characterizations for boundedness, essential norm and compactness of generalized Stevic-Sharma type operators from Hardy spaces into $n$th weighted type spaces are given.


On B-Generalized Skew Derivations In Banach Algebras, Abdul Nadim Khan Jan 2021

On B-Generalized Skew Derivations In Banach Algebras, Abdul Nadim Khan

Turkish Journal of Mathematics

} Let $\mathscr{A}$ be a Banach algebra over $\mathbb{R}$ or $\mathbb{C}$. In this paper, we describe the behavior of recently defined $b$-generalized skew derivations which satisfy certain differential identities on some specific subsets of $\mathscr{A}$.


Fundamental Group Of Galois Covers Of Degree 5 Surfaces, Meirav Amram, Cheng Gong, Mina Teicher, Wan-Yuan Xu Jan 2021

Fundamental Group Of Galois Covers Of Degree 5 Surfaces, Meirav Amram, Cheng Gong, Mina Teicher, Wan-Yuan Xu

Turkish Journal of Mathematics

Let $X$ be an algebraic surface of degree $5$, which is considered a branch cover of $\mathbb{CP}^2$ with respect to a generic projection. The surface has a natural Galois cover with Galois group $S_5$. In this paper, we deal with the fundamental groups of Galois covers of degree $5$ surfaces that degenerate to nice plane arrangements; each of them is a union of five planes such that no three planes meet in a line.


Logarithmic Dimension And Bases In Whitney Spaces, Alexander Goncharov, Yasemi̇n Şengül Tezel Jan 2021

Logarithmic Dimension And Bases In Whitney Spaces, Alexander Goncharov, Yasemi̇n Şengül Tezel

Turkish Journal of Mathematics

We give a formula for the logarithmic dimension of the generalized Cantor-type set $K$. In the case when the logarithmic dimension of $K$ is smaller than $1$, we construct a Faber basis in the space of Whitney functions $\mathcal{E}(K)$.


B-Property Of Sublattices In Vector Lattices, Ömer Şafak Alpay, Svetlana Gorokhova Jan 2021

B-Property Of Sublattices In Vector Lattices, Ömer Şafak Alpay, Svetlana Gorokhova

Turkish Journal of Mathematics

We study $b$-property of a sublattice (or an order ideal) $F$ of a vector lattice $E$. In particular, $b$-property of $E$ in $E^\delta$, the Dedekind completion of $E$, $b$-property of $E$ in $E^u$, the universal completion of $E$, and $b$-property of $E$ in $\hat{E}(\hat{\tau})$, the completion of $E$.


On Congruences Related To Trinomial Coefficients And Harmonic Numbers, Neşe Ömür, Si̇bel Koparal, Laid Elkhiri Jan 2021

On Congruences Related To Trinomial Coefficients And Harmonic Numbers, Neşe Ömür, Si̇bel Koparal, Laid Elkhiri

Turkish Journal of Mathematics

In this paper, we establish some congruences involving the trinomial coefficients and harmonic numbers. For example, for any prime $p>3,$ \begin{equation*} \sum\limits_{k=0}^{p-1}\left( -1\right) ^{k}\binom{p-1}{k}_{2}H_{k}\equiv 0 \ \pmod {p}. \end{equation*}


Relative Conics And Their Brianchon Points, Magdalena Lampa-Baczynska, Daniel Wojcik Jan 2021

Relative Conics And Their Brianchon Points, Magdalena Lampa-Baczynska, Daniel Wojcik

Turkish Journal of Mathematics

The purpose of this paper is to study some additional relations between lines and points in the configuration of six lines tangent to the common conic. One of the most famous results concerning with this configuration is Brianchon theorem. It says that three diagonals of a hexagon circumscribing around conic are concurrent. They meet in the so called Brianchon point. In fact, by relabeling the vertices of hexagon, we obtain $60$ distinct Brianchon points. We prove, among others, that, in the set of all intersection points of six tangents to the same conic, there exist exactly $10$ sextuples of points …


Ideal Triangulation And Disc Unfolding Of A Singular Flat Surface, İsmai̇l Sağlam Jan 2021

Ideal Triangulation And Disc Unfolding Of A Singular Flat Surface, İsmai̇l Sağlam

Turkish Journal of Mathematics

An ideal triangulation of a singular flat surface is a geodesic triangulation such that its vertex set is equal to the set of singular points of the surface. Using the fact that each pair of points in a surface has a finite number of geodesics having length $\leq L$ connecting them, where $L$ is any positive number, we prove that each singular flat surface has an ideal triangulation provided that the surface has singular points when it has no boundary components, or each of its boundary components has a singular point. Also, we prove that such a surface contains a …


A Refinement Of The Bergström Inequality, Gülteki̇n Tinaztepe, İlknur Yeşi̇lce, Gabi̇l Adi̇lov Jan 2021

A Refinement Of The Bergström Inequality, Gülteki̇n Tinaztepe, İlknur Yeşi̇lce, Gabi̇l Adi̇lov

Turkish Journal of Mathematics

In this paper, the Bergstrom inequality is studied, and a refinement of this inequality is obtained by performing the optimality conditions based on abstract concavity. Some numerical experiments are given to illustrate the efficacy of the refinement.


On The Spectra Of Generalized Fibonomial And Jacobsthal-Binomial Graphs, Hati̇ce Topcu, Nurten Yücel Jan 2021

On The Spectra Of Generalized Fibonomial And Jacobsthal-Binomial Graphs, Hati̇ce Topcu, Nurten Yücel

Turkish Journal of Mathematics

In this work, we first give a more general form of the binomial, Fibonomial, and balance-binomial graphs that is called generalized Fibonomial graph. We also argue the spectra of generalized Fibonomial graph. Next, we introduce a new type of graph on Jacobsthal numbers that is called Jacobsthal-binomial graph and denoted by $JB_{n}$. We obtain the adjacency, Laplacian and signless Laplacian characteristic polynomials of $JB_{n}$, respectively. We lastly give inequalities for the adjacency, Laplacian and signless Laplacian energies of $JB_{n}$.


Ranks Of Nilpotent Subsemigroups Of Order-Preserving And Decreasing Transformation Semigroups, Emrah Korkmaz, Hayrullah Ayik Jan 2021

Ranks Of Nilpotent Subsemigroups Of Order-Preserving And Decreasing Transformation Semigroups, Emrah Korkmaz, Hayrullah Ayik

Turkish Journal of Mathematics

Let $\mathcal{C}_{n}$ be the semigroup of all order-preserving and decreasing transformations on $X=\{1,\ldots ,n\}$ under its natural order, and let $N(\mathcal{C}_{n})$ be the subsemigroup of all nilpotent elements of $\mathcal{C}_{n}$. For $1\leq r \leq n-1$, let \begin{eqnarray*} N(\mathcal{C}_{n,r})&=&\{ \alpha\in N(\mathcal{C}_{n}) : \lvert im(\alpha)\rvert \leq r\} ,\\ N_{r}(\mathcal{C}_{n})&=&\{\alpha\in N\mathcal({C}_{n}):\alpha\mbox{ is an } m\mbox{-potent for any } 1\leq m\leq r\} . \end{eqnarray*} In this paper we find the cardinality and the rank of the subsemigroup $N(\mathcal{C}_{n,r})$ of $\mathcal{C}_{n}$. Moreover, we show that the set $N_{r}(\mathcal{C}_{n})$ is a subsemigroup of $N(\mathcal{C}_{n})$ and then, we find a lower bound for the rank of $N_{r}(\mathcal{C}_{n})$.


On The Local And Global Stability Of An Sirs Epidemic Model With Logistic Growth And Information Intervention, İrem Çay Jan 2021

On The Local And Global Stability Of An Sirs Epidemic Model With Logistic Growth And Information Intervention, İrem Çay

Turkish Journal of Mathematics

In this study, we investigate an susceptible-infected-recovered-susceptible (SIRS) epidemic model with logistic growth and information intervention. Firstly, the basic reproduction number $R_0$ is defined and the main results are given in terms of local stability. Then, sufficient conditions for the global stability of endemic equilibrium are obtained. Finally, some numerical simulations are given to validate our theoretical conclusions.


Decompositions Of Complete Symmetric Directed Graphs Into The Oriented Heptagons, Uğur Odabaşi Jan 2021

Decompositions Of Complete Symmetric Directed Graphs Into The Oriented Heptagons, Uğur Odabaşi

Turkish Journal of Mathematics

The complete symmetric directed graph of order $v$, denoted by $K_{v}$, is the directed graph on $v$~vertices that contains both arcs $(x,y)$ and $(y,x)$ for each pair of distinct vertices $x$ and~$y$. For a given directed graph $D$, the set of all $v$ for which $K_{v}$ admits a $D$-decomposition is called the spectrum of~$D$-decomposition. There are 10 nonisomorphic orientations of a $7$-cycle (heptagon). In this paper, we completely settled the spectrum problem for each of the oriented heptagons.


On Hilbert Genus Fields Of Imaginary Cyclic Quartic Fields, Moulay Ahmed Hajjami, Mohamed Mahmoud Chems Eddin Jan 2021

On Hilbert Genus Fields Of Imaginary Cyclic Quartic Fields, Moulay Ahmed Hajjami, Mohamed Mahmoud Chems Eddin

Turkish Journal of Mathematics

Let $p$ be a prime number such that $p=2$ or $p\equiv 1\pmod 4$. Let $\varepsilon_p$ denote the fundamental unit of $\mathbb{Q}(\sqrt{p})$ and let $a$ be a positive square-free integer. The main aim of this paper is to determine explicitly the Hilbert genus field of the imaginary cyclic quartic fields of the form $\mathbb{Q}(\sqrt{-a\varepsilon_p\sqrt{p}})$.


Conformal Bi-Slant Submersions, Sezi̇n Aykurt Sepet Jan 2021

Conformal Bi-Slant Submersions, Sezi̇n Aykurt Sepet

Turkish Journal of Mathematics

In this paper, we study conformal bi-slant submersions from almost Hermitian manifolds onto Riemannian manifolds as a generalized of conformal anti-invariant, conformal semi-invariant, conformal semi-slant, conformal slant, and conformal hemi-slant submersions. We investigate the integrability of distributions and obtain necessary and sufficient conditions for the maps to have totally geodesic fibers. Also, we consider some decomposition theorems for the new submersion and study the total geodesicity of such maps. Finally, we find curvature relations between the base space and the total space.


C_11 Modules Via Left Exact Preradicals, Ramazan Yaşar Jan 2021

C_11 Modules Via Left Exact Preradicals, Ramazan Yaşar

Turkish Journal of Mathematics

In this article, we study modules with the condition that every image of a submodule under a left exact preradical has a complement which is a direct summand. This new class of modules properly contains the class of $C_{11}$-modules (and hence also $CS$-modules). Amongst other structural properties, we deal with direct sums and decompositions with respect to the left exact preradicals of this new class of modules. It is obtained a decomposition such that the image of the module itself is a direct summand for the left exact radical, which enjoys the new condition.


Global Attractivity Of Delay Difference Equations In Banach Spaces Via Fixed-Point Theory, Abdullah Kalkan Jan 2021

Global Attractivity Of Delay Difference Equations In Banach Spaces Via Fixed-Point Theory, Abdullah Kalkan

Turkish Journal of Mathematics

We formulate initial value problems for delay difference equations in Banach spaces as fixed-point problems in sequence spaces. By choosing appropriate sequence spaces various types of attractivity can be described. This allows us to establish global attractivity by means of fixed-point results. Finally, we provide an application to delay integrodifference equations in the space of continuous functions over a compact domain.


A Regularized Trace Formula For "Weighted" Sturm-Liouville Equation With Point Delta-Interaction, Manaf Manafli Jan 2021

A Regularized Trace Formula For "Weighted" Sturm-Liouville Equation With Point Delta-Interaction, Manaf Manafli

Turkish Journal of Mathematics

In this study, we obtain a formula for the regularized trace formula for "weighted" Sturm--Liouville equation with point $\delta $- interaction. At the begining, for the correct determination of solutions of analyzed equation at the point of discontinuty, the matching conditions are required. As a result, an equation is derived for the eigenvalues of the differential operator given in this study.


Some Properties Of The Semigroup $Pg_Y(X)$: Green's Relations, Ideals, Isomorphism Theorems And Ranks, Worachead Sommanee Jan 2021

Some Properties Of The Semigroup $Pg_Y(X)$: Green's Relations, Ideals, Isomorphism Theorems And Ranks, Worachead Sommanee

Turkish Journal of Mathematics

Let $T(X)$ be the full transformation semigroup on the set $X$. For a fixed nonempty subset $Y$ of $X$, let \begin{equation*} PG_Y(X) = \{\alpha\in T(X) : \alpha _Y\in G(Y)\} \end{equation*} where $G(Y)$ is the permutation group on $Y$. It is known that $PG_Y(X)$ is a regular subsemigroup of $T(X)$. In this paper, we give a simpler description of Green's relations and characterize the ideals of $PG_Y(X)$. Moreover, we prove some isomorphism theorems for $PG_Y(X)$. For finite sets, we investigate the cardinalities of $PG_Y(X)$ and of its subsets of idempotents, and we also calculate their ranks.


Domination Parameters On Cayley Digraphs Of Transformation Semigroups With Fixed Sets, Nuttawoot Nupo, Chollawat Pookpienlert Jan 2021

Domination Parameters On Cayley Digraphs Of Transformation Semigroups With Fixed Sets, Nuttawoot Nupo, Chollawat Pookpienlert

Turkish Journal of Mathematics

For a nonempty subset $Y$ of a nonempty set $X$, denote by $Fix(X,Y)$ the semigroup of full transformations on the set $X$ in which all elements in $Y$ are fixed. The Cayley digraph $Cay$ $(Fix(X,Y),A)$ of $Fix(X,Y)$ with respect to a connection set $A\subseteq Fix(X,Y)$ is defined as a digraph whose vertex set is $Fix(X,Y)$ and two vertices $\alpha, \beta$ are adjacent in sense of drawing a directed edge (arc) from $\alpha$ to $\beta$ if there exists $\mu\in A$ such that $\beta = \alpha\mu$. In this paper, we determine domination parameters of $Cay$ $(Fix(X,Y),A)$ where $A$ is a subset of …


General Characteristics Of A Fractal Sturm-Liouville Problem, Fatma Ayça Çeti̇nkaya, Alireza Khalili Golmankaneh Jan 2021

General Characteristics Of A Fractal Sturm-Liouville Problem, Fatma Ayça Çeti̇nkaya, Alireza Khalili Golmankaneh

Turkish Journal of Mathematics

In this paper, we consider a regular fractal Sturm-Liouville boundary value problem. We prove the self-adjointness of the differential operator which is generated by the $F^\alpha$-derivative introduced in [32]. We obtained the $F^\alpha$-analogue of Liouville's theorem, and we show some properties of eigenvalues and eigenfunctions. We present examples to demonstrate the efficiency and applicability of the obtained results. The findings of this paper can be regarded as a contribution to an emerging field.


Half Inverse Problems For The Impulsive Quadratic Pencil With The Discontinouty Coefficient, Rauf Ami̇rov, Sevi̇m Durak Jan 2021

Half Inverse Problems For The Impulsive Quadratic Pencil With The Discontinouty Coefficient, Rauf Ami̇rov, Sevi̇m Durak

Turkish Journal of Mathematics

In this paper, we study the inverse spectral problem for the quadratic differential pencils with discontinuity coefficient on $\left[ 0,\pi\right] $ with separable boundary conditions and the impulsive conditions at the point $x=\dfrac{\pi}{2}$. We prove that two potential functions on the interval $\left[ 0,\pi\right] $, and the parameters in the boundary and impulsive conditions can be determined from a sequence of eigenvalues for two cases: (i) The potentials are given on $\left( 0,\dfrac{\pi}{4}\left( 1+\alpha\right) \right) ,$ (ii) The potentials are given on $\left( \dfrac{\pi}{4}\left( 1+\alpha\right) ,\pi\right) $, where $0