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Discrete Fractional Integrals, Lattice Points On Short Arcs, And Diophantine Approximation, Faruk Temur Jan 2022

Discrete Fractional Integrals, Lattice Points On Short Arcs, And Diophantine Approximation, Faruk Temur

Turkish Journal of Mathematics

Recently in joint work with E. Sert, we proved sharp boundedness results on discrete fractional integral operators along binary quadratic forms. Present work vastly enhances the scope of those results by extending boundedness to bivariate quadratic polynomials. We achieve this in part by establishing connections to problems on concentration of lattice points on short arcs of conics, whence we study discrete fractional integrals and lattice point concentration from a unified perspective via tools of sieving and diophantine approximation, and prove theorems that are of interest to researchers in both subjects.


Nonic B-Spline Algorithms For Numerical Solution Of The Kawahara Equation, Meli̇s Zorşahi̇n Görgülü Jan 2022

Nonic B-Spline Algorithms For Numerical Solution Of The Kawahara Equation, Meli̇s Zorşahi̇n Görgülü

Turkish Journal of Mathematics

In this paper, the nonic (9th order) B-spline functions which have not been used before for the numerical solutions of the partial differential equations by finite element methods are used to solve numerically the Kawahara equation. These approaches involve the collocation and Galerkin finite element methods based on the nonic B-spline functions in space discretization and second order scheme (Crank-Nicolson method) in time discretization. To see the accuracy of the proposed methods three test problems are demonstrated and the obtained numerical results for both of the methods are compared with the exact solution of the Kawahara equation.


On The Bmo Spaces Associated With The Laplace-Bessel Differential Operator, Si̇nem Sezer, Si̇mten Bayrakçi, Güldane Yildiz, Recep Kahraman Jan 2022

On The Bmo Spaces Associated With The Laplace-Bessel Differential Operator, Si̇nem Sezer, Si̇mten Bayrakçi, Güldane Yildiz, Recep Kahraman

Turkish Journal of Mathematics

In this paper, the characteristic properties of the space of functions of bounded mean oscillation called the $B$-$BMO$ associated with the Laplace-Bessel differential operator are obtained. The John-Nirenberg type inequality on the $B$-$BMO$ space and a relation between the $B$-Poisson integral and the $B$-$BMO$ functions are proved.


Ulam's Type Stability Analysis Of Fractional Difference Equation With Impulse: Gronwall Inequality Approach, Rabia Ilyas, Mujeeb Ur Rehman Jan 2022

Ulam's Type Stability Analysis Of Fractional Difference Equation With Impulse: Gronwall Inequality Approach, Rabia Ilyas, Mujeeb Ur Rehman

Turkish Journal of Mathematics

In this paper, we present a new Gronwall inequality with an impulsive effect. The existence and uniqueness of the solution is investigated through fixed point theorems. Moreover, with the help of newly developed inequality Ulam's type stability criterion is developed for impulsive fractional difference equation. At last, a model is given to help the hypothetical outcome.


Nonunique Best Proximity Point Results With An Application To Nonlinear Fractional Differential Equations, Mustafa Aslantaş Jan 2022

Nonunique Best Proximity Point Results With An Application To Nonlinear Fractional Differential Equations, Mustafa Aslantaş

Turkish Journal of Mathematics

In this paper, we point out an error in proving famous Achari type nonunique fixed point results. Also, we prove some best proximity point results in $b$ -metric spaces by introducing new concepts. Hence, we develop some results existing in the literature. Finally, we give a result for the existence of the solution of nonlinear fractional differential equations.


Existence And Uniqueness Of Mild Solutions For Mixed Caputo And Riemann-Liouville Semilinear Fractional Integrodifferential Equations With Nonlocal Conditions, Ashraf H. A. Radwan Jan 2022

Existence And Uniqueness Of Mild Solutions For Mixed Caputo And Riemann-Liouville Semilinear Fractional Integrodifferential Equations With Nonlocal Conditions, Ashraf H. A. Radwan

Turkish Journal of Mathematics

The purpose of this paper is to investigate the existence and uniqueness of the mild solution to a class of semilinear fractional integrodifferential equations with state-dependent nonlocal fractional conditions. Our problem includes both Caputo and Riemann-Liouville fractional derivatives. Continuous dependence of solutions on initial conditions and $\epsilon$-approximate mild solutions of the considered problem will be discussed.


Classical Solutions For 1-Dimensional And 2-Dimensional Boussinesq Equations, Svetlin Georgiev, Aissa Boukarou, Khaled Zennir Jan 2022

Classical Solutions For 1-Dimensional And 2-Dimensional Boussinesq Equations, Svetlin Georgiev, Aissa Boukarou, Khaled Zennir

Turkish Journal of Mathematics

In this article we investigate the IVPs for 1-dimensional and 2-dimensional Boussinesq equations. A new topological approach is applied to prove the existence of at least one classical solution and at least two nonnegative classical solutions for the considered IVPs. The arguments are based upon recent theoretical results.


New Form Of Laguerre Fractional Differential Equation And Applications, Zahra Kavooci, Kazem Ghanbari, Hanif Mirzaei Jan 2022

New Form Of Laguerre Fractional Differential Equation And Applications, Zahra Kavooci, Kazem Ghanbari, Hanif Mirzaei

Turkish Journal of Mathematics

Laguerre differential equation is a well known equation that appears in the quantum mechanical description of the hydrogen atom. In this paper, we aim to develop a new form of Laguerre Fractional Differential Equation (LFDE) of order $2\alpha$ and we investigate the solutions and their properties. For a positive real number $\alpha$, we prove that the equation has solutions of the form $L_{n,\alpha}(x)=\sum_{k=0}^na_kx^k$, where the coefficients of the polynomials are computed explicitly. For integer case $\alpha=1$ we show that these polynomials are identical to classical Laguerre polynomials. Finally, we solve some fractional differential equations by defining a suitable integral transform.


Solving A Class Of Ordinary Differential Equations And Fractional Differential Equations With Conformable Derivative By Fractional Laplace Transform, Mohammad Molaei, Farhad Dastmalchi Saei, Mohammad Javidi, Yaghoub Mahmoudi Jan 2022

Solving A Class Of Ordinary Differential Equations And Fractional Differential Equations With Conformable Derivative By Fractional Laplace Transform, Mohammad Molaei, Farhad Dastmalchi Saei, Mohammad Javidi, Yaghoub Mahmoudi

Turkish Journal of Mathematics

In this paper, we use the fractional Laplace transform to solve a class of second-order ordinary differential equations (ODEs), as well as some conformable fractional differential equations (CFDEs), including the Laguerre conformable fractional differential equation. Specifically, we apply the transform to convert the differential equations into first-order, linear differential equations. This is done by using the fractional Laplace transform of order $\alpha+\beta$ or $\alpha+\beta+\gamma$. Also, we investigate some more results on the fractional Laplace transform, obtained by Abdeljawad.


Oscillation Of Second Order Mixed Functional Differential Equations With Sublinear And Superlinear Neutral Terms, Shan Shi, Zhenlai Han Jan 2022

Oscillation Of Second Order Mixed Functional Differential Equations With Sublinear And Superlinear Neutral Terms, Shan Shi, Zhenlai Han

Turkish Journal of Mathematics

In this paper, we shall establish some new oscillation theorems for the functional differential equations with sublinear and superlinear neutral terms of the form $$ (r(t)(z'(t))^\alpha)'=q(t)x^\alpha(\tau(t)), $$ where $z(t)=x(t)+p_1(t)x^\beta(\sigma(t))-p_2(t)x^\gamma(\sigma(t))$ with $0


Some Recent Results In Plastic Structure On Riemannian Manifold, Akbar Dehghan Nezhad, Zohreh Aral Jan 2022

Some Recent Results In Plastic Structure On Riemannian Manifold, Akbar Dehghan Nezhad, Zohreh Aral

Turkish Journal of Mathematics

The plastic ratio is a fascinating topic that continually generates new ideas. The purpose of this paper is to point out and find some applications of the plastic ratio in the differential manifold. Precisely, we say that an $(1,1)$-tensor field $P$ on a $m$-dimensional Riemannian manifold $(M, g)$ is a plastic structure if it satisfies the equation $ P^3 = P + I $, where $ I $ is the identity. We establish several properties of the plastic structure. Then we show that a plastic structure induces on every invariant submanifold a plastic structure, too.


Oscillation Of Third-Order Neutral Differential Equations With Oscillatory Operator, Miroslav Bartusek Jan 2022

Oscillation Of Third-Order Neutral Differential Equations With Oscillatory Operator, Miroslav Bartusek

Turkish Journal of Mathematics

A third-order damped neutral sublinear differential equation for which its differential operator is oscillatory is studied. Sufficient conditions are given under which every solution is either oscillatory or the derivative of its neutral term is oscillatory (or it tends to zero).


$K$-Generalized Pell Numbers Which Are Repdigits In Base $B$, Zafer Şi̇ar, Refi̇k Keski̇n Jan 2022

$K$-Generalized Pell Numbers Which Are Repdigits In Base $B$, Zafer Şi̇ar, Refi̇k Keski̇n

Turkish Journal of Mathematics

Let $k\geq 2$ be an integer and let $(P_{n}^{(k)})_{n\geq 2-k}$ be the $k$ -generalized Pell sequence defined by \begin{equation*} P_{n}^{(k)}=2P_{n-1}^{(k)}+P_{n-2}^{(k)}+...+P_{n-k}^{(k)} \end{equation*} for $n\geq 2$ with initial conditions \begin{equation*} P_{-(k-2)}^{(k)}=P_{-(k-3)}^{(k)}=\cdot \cdot \cdot =P_{-1}^{(k)}=P_{0}^{(k)}=0,P_{1}^{(k)}=1. \end{equation*} In this study, we deal with the Diophantine equation \begin{equation*} P_{n}^{(k)}=d\left( \frac{b^{m}-1}{b-1}\right) \end{equation*} in positive integers $n,m,k,b,d$ such that $m\geq 2,$ $2\leq b\leq 9$ and $ 1\leq d\leq b-1$. We show that the repdigits in the base $b$ in the $k-$ generalized Pell sequence, which have at least two digits, are the numbers \begin{eqnarray*} \ P_{7}^{(4)} &=&228=(444)_{7},\text{ }P_{4}^{(2)}=12=(22)_{5}\text{, }% P_{6}^{(2)}=70=(77)_{9}\text{;} \\ P_{4}^{(k)} &=&13=(111)_{3}\text{ } \end{eqnarray*} for $k\geq …


On A Subclass Of The Analytic And Bi-Univalent Functions Satisfying Subordinate Condition Defined By $Q$-Derivativ, Ni̇zami̇ Mustafa, Semra Korkmaz Jan 2022

On A Subclass Of The Analytic And Bi-Univalent Functions Satisfying Subordinate Condition Defined By $Q$-Derivativ, Ni̇zami̇ Mustafa, Semra Korkmaz

Turkish Journal of Mathematics

In this paper, we introduce and examine certain subclass $\ M_{q,\Sigma }\left( \varphi ,\beta \right) $ of analytic and bi-univalent functions on the open unit disk in the complex plane. Here, we give coefficient bound estimates, upper bound estimate for the second Hankel determinant and Fekete-Szegö inequality for the function belonging to this class. Some interesting special cases of the results obtained here are also discussed.


A Galerkin-Type Approach To Solve Systems Of Linear Volterra-Fredholm Integro-Differential Equations, Murat Karaçayir, Şuayi̇p Yüzbaşi Jan 2022

A Galerkin-Type Approach To Solve Systems Of Linear Volterra-Fredholm Integro-Differential Equations, Murat Karaçayir, Şuayi̇p Yüzbaşi

Turkish Journal of Mathematics

The main interest of this paper is to propose a numerical scheme in order to solve linear systems of Volterra-Fredholm integro-differential equations given with mixed conditions. The proposed method is a weighted residual scheme which uses monomials up to a prescribed degree $N$ as the basis functions. By taking inner product of the equation system with the elements of this basis set in a Galerkin-like fashion, the original problem is transformed into a linear algebraic equation system. After a suitable incorporation of the mixed conditions, a final algebraic system is obtained, from which the approximate solutions of the problem are …


Continuous Wavelet Transform On Triebel-Lizorkin Spaces, Antonio L. Baisón Olmo, Víctor A. Cruz Barriguete, Jaime Navarro Jan 2022

Continuous Wavelet Transform On Triebel-Lizorkin Spaces, Antonio L. Baisón Olmo, Víctor A. Cruz Barriguete, Jaime Navarro

Turkish Journal of Mathematics

The continuous wavelet transform in higher dimensions is used to prove the regularity of weak solutions $u \in L^p(\mathbb R^n)$ under $Qu = f$ where $f$ belongs to the Triebel-Lizorkin space $F^{r,q}_p(\mathbb R^n)$ where $1 < p,q < \infty$, $0< r 0$ with positive constant coefficients $c_{\beta}$.


On The Behaviour Of Solutions To A Kind Of Third Order Nonlinear Neutral Differential Equation With Delay, Adeleke Ademola, Peter Arawomo, Olufemi Adesina, Samuel Okoya Jan 2022

On The Behaviour Of Solutions To A Kind Of Third Order Nonlinear Neutral Differential Equation With Delay, Adeleke Ademola, Peter Arawomo, Olufemi Adesina, Samuel Okoya

Turkish Journal of Mathematics

This paper presents a novel class of third order nonlinear nonautonomous neutral differential equation with delay. The third order neutral differential equation is cut down to a system of first order, a suitable complete Lyapunov-Krasovskii's functional is constructed and used, to obtain standard conditions on the nonlinear functions to ensure stability and uniform asymptotic stability of the trivial solutions, the existence of a unique periodic solution, uniform boundedness and uniform ultimate boundedness of solutions when the forcing term is nonzero. The obtained results are new and include many prominent results on neutral and nonneutral delay differential equations in literature. Finally, …


Constant Angle Surfaces In The Lorentzian Warped Product Manifold $I \Times_{F} \Mathbb E^2_1$, Uğur Dursun Jan 2022

Constant Angle Surfaces In The Lorentzian Warped Product Manifold $I \Times_{F} \Mathbb E^2_1$, Uğur Dursun

Turkish Journal of Mathematics

Let $I \times_{f} \mathbb E^2_1$ be a 3-dimensional Lorentzian warped product manifold with the metric $\tilde g = dt^2 + f^2(t) (dx^2 - dy^2)$, where $I$ is an open interval, $f$ is a strictly positive smooth function on $I,$ and $\mathbb E^2_1$ is the Minkowski 2-plane. In this work, we give a classification of all space-like and time-like constant angle surfaces in $I \times_{f} \mathbb E^2_1$ with nonnull principal direction when the surface is time-like. In this classification, we obtain space-like and time-like surfaces with zero mean curvature, rotational surfaces, and surfaces with constant Gaussian curvature. Also, we have some …


Novel Exact Solutions To Navier-Stokes Momentum Equations Describing An Incompressible Fluid, Yahya Öz Jan 2022

Novel Exact Solutions To Navier-Stokes Momentum Equations Describing An Incompressible Fluid, Yahya Öz

Turkish Journal of Mathematics

An analytical solution to the incompressible Navier-Stokes momentum equations for a divergence-free flow $\boldsymbol{\nabla}\cdot \vec u\left(\vec x,t\right)=0$ with time-dependent dynamic viscosity $\mu\left(t\right)$ is presented. The demonstrated methodology holds for the physically relevent three dimensions. The constructed flow velocities $\vec u\left(\vec x,t\right)$ are eigenvectors of the vector operator curl. Moreover, vortex $\vec \omega\left(\vec x,t\right)$, helicity $H\left(\vec x,t\right)$, enstrophy $\mathcal{E}\left(t\right)$ and enstrophy evolution $\frac{\mathrm{d}\mathcal{E}\left(t\right)}{\mathrm{d}t}$ are explicitly determined.


Explicit Motion Planning In Digital Projective Product Spaces, Seher Fi̇şekci̇, İsmet Karaca Jan 2022

Explicit Motion Planning In Digital Projective Product Spaces, Seher Fi̇şekci̇, İsmet Karaca

Turkish Journal of Mathematics

We introduce digital projective product spaces based on Davis' projective product spaces. We determine an upper bound for the digital LS-category of digital projective product spaces. In addition, we obtain an upper bound for the digital topological complexity of these spaces through an explicit motion planning construction, which shows digital perspective validity of results given by S. Fişekci and L. Vandembroucq. We apply our outcomes on specific spaces in order to be more clear.


The Fourier Spectral Method For Determining A Heat Capacity Coefficient In A Parabolic Equation, Durdimurod Durdiev, Dilshod Durdiev Jan 2022

The Fourier Spectral Method For Determining A Heat Capacity Coefficient In A Parabolic Equation, Durdimurod Durdiev, Dilshod Durdiev

Turkish Journal of Mathematics

In this paper, the comparison of finite difference and Fourier spectral numerical methods for an inverse problem of simultaneously determining an unknown coefficient in a parabolic equation with the usual initial and boundary conditions is proposed. We represent the detailed description of the methods and their algorithms. The research work conducted in this paper shows that the Fourier spectral method is highly accurate.


$3d$-Flows Generated By The Curl Of A Vector Potential & Maurer-Cartan Equations, Oğul Esen, Partha Guha, Hasan Gümral Jan 2022

$3d$-Flows Generated By The Curl Of A Vector Potential & Maurer-Cartan Equations, Oğul Esen, Partha Guha, Hasan Gümral

Turkish Journal of Mathematics

We examine $3D$ flows $\mathbf{\dot{x}}=\mathbf{v}({\bf x})$ admitting vector identity $M\mathbf{v} = \nabla \times \mathbf{A}$ for a multiplier $M$ and a potential field $\mathbf{A}$. It is established that, for those systems, one can complete the vector field $\mathbf{v}$ into a basis fitting an $\mathfrak{sl}(2)$-algebra. Accordingly, in terms of covariant quantities, the structure equations determine a set of equations in Maurer-Cartan form. This realization permits one to obtain the potential field as well as to investigate the (bi-)Hamiltonian character of the system. The latter occurs if the system has a time-independent first integral. In order to exhibit the theoretical results on some …


Translating Solitons Of Translation And Homothetical Types, Muhi̇tti̇n Evren Aydin, Rafael Lopez Jan 2022

Translating Solitons Of Translation And Homothetical Types, Muhi̇tti̇n Evren Aydin, Rafael Lopez

Turkish Journal of Mathematics

We prove that if a translating soliton can be expressed as the sum of two curves and one of these curves is planar, then the other curve is also planar and consequently the surface must be a plane or a grim reaper. We also investigate translating solitons that can be locally written as the product of two functions of one variable. We extend the results in Lorentz-Minkowski space.


From Ordered Semigroups To Ordered $\Gamma$-Hypersemigroups, Niovi Kehayopulu Jan 2022

From Ordered Semigroups To Ordered $\Gamma$-Hypersemigroups, Niovi Kehayopulu

Turkish Journal of Mathematics

In an attempt to show the way we pass from ordered semigroups to ordered $\Gamma$-hypersemigroups, we examine the results of Semigroup Forum (1992; 46: 341-346) for an ordered $\Gamma$-hypersemigroup. It has been shown that the concept of semisimple ordered $\Gamma$-hypersemigroup $S$ is identical with the concept "the ideals of $S$ are idempotent" and the ideals of $S$ are idempotent if and only if for all ideals $A, B$ of $S$, we have $A\cap B=(A\Gamma B]$. The main results of the paper are the following: The ideals of an ordered $\Gamma$-hypersemigroup $S$ are weakly prime if and only if they form …


Bessel Equation And Bessel Function On $\Mathbb{T}_{(Q,H)}$, Ahmet Yantir, Burcu Si̇li̇ndi̇r Yantir, Zehra Tuncer Jan 2022

Bessel Equation And Bessel Function On $\Mathbb{T}_{(Q,H)}$, Ahmet Yantir, Burcu Si̇li̇ndi̇r Yantir, Zehra Tuncer

Turkish Journal of Mathematics

This article is devoted to present nabla $(q, h)$-analogues of Bessel equation and Bessel function. In order to construct series solution of nabla $(q, h)$-Bessel equation, we present nabla $(q, h)$-analysis regarding nabla generalized quantum binomial, nabla $(q,h)$-analogues of Taylor's formula, Gauss's binomial formula, Taylor series, analytic functions, analytic exponential function with its fundamental properties, analytic trigonometric and hyperbolic functions. We emphasize that nabla $(q, h)$-Bessel equation recovers classical, $h$- and $q$-discrete Bessel equations. In addition, we establish nabla $(q, h)$-Bessel function which is expressed in terms of an absolutely convergent series in nabla generalized quantum binomials and intimately demonstrate …


The Interior-Boundary Strichartz Estimate For The Schrödinger Equation On The Half-Line Revisited, Bi̇lge Köksal, Türker Özsari Jan 2022

The Interior-Boundary Strichartz Estimate For The Schrödinger Equation On The Half-Line Revisited, Bi̇lge Köksal, Türker Özsari

Turkish Journal of Mathematics

In recent papers, it was shown for the biharmonic Schrödinger equation and 2D Schrödinger equation that Fokas method-based formulas are capable of defining weak solutions of associated nonlinear initial boundary value problems (ibvps) below the Banach algebra threshold. In view of these results, we revisit the theory of interior-boundary Strichartz estimates for the Schrödinger equation posed on the right half line, considering both Dirichlet and Neumann cases. Finally, we apply these estimates to obtain low regularity solutions for the nonlinear Schrödinger equation (NLS) with Neumann boundary condition and a coupled system of NLS equations defined on the half line with …


2-Colored Rogers-Ramanujan Partition Identities, Mohammad Zadehdabbagh Jan 2022

2-Colored Rogers-Ramanujan Partition Identities, Mohammad Zadehdabbagh

Turkish Journal of Mathematics

In this paper, we combined two types of partitions and introduced 2-colored Rogers-Ramanujan partitions. By finding some functional equations and using a constructive method, some identities have been found. Some overpartition identities coincide with our findings. A correspondence between colored partitions and overpartitions is provided.


Maximising The Number Of Connected Induced Subgraphs Of Unicyclic Graphs, Audace A V Dossou Olory Jan 2022

Maximising The Number Of Connected Induced Subgraphs Of Unicyclic Graphs, Audace A V Dossou Olory

Turkish Journal of Mathematics

Denote by $\mathcal{G}(n,c,g,k)$ the set of all connected graphs of order $n$, having $c$ cycles, girth $g$, and $k$ pendant vertices. In this paper, we give a partial characterisation of the structure of those graphs in $\mathcal{G}(n,c,g,k)$ maximising the number of connected induced subgraphs. For the special case where $c=1$, we find a complete characterisation of all maximal unicyclic graphs. We also derive a precise formula for the corresponding maximum number given the following parameters: (1) order, girth, and number of pendant vertices; (2) order and girth; (3) order.


On Generalized Fibonacci And Lucas Hybrid Polynomials, N. Rosa Ait-Amrane, Hacene Belbachir, Eli̇f Tan Jan 2022

On Generalized Fibonacci And Lucas Hybrid Polynomials, N. Rosa Ait-Amrane, Hacene Belbachir, Eli̇f Tan

Turkish Journal of Mathematics

In this paper, we introduce a new generalization of Fibonacci and Lucas hybrid polynomials. We investigate some basic properties of these polynomials such as recurrence relations, the generating functions, the Binet formulas, summation formulas, and a matrix representation. We derive generalized Cassini's identity and generalized Honsberger formula for generalized Fibonacci hybrid polynomials by using their matrix representation.


Numerical Solution Of A Singularly Perturbed Fredholm Integro Differential Equation With Robin Boundary Condition, Muhammet Enes Durmaz, Gabi̇l Ami̇rali̇, Mustafa Kudu Jan 2022

Numerical Solution Of A Singularly Perturbed Fredholm Integro Differential Equation With Robin Boundary Condition, Muhammet Enes Durmaz, Gabi̇l Ami̇rali̇, Mustafa Kudu

Turkish Journal of Mathematics

In this paper, we deal with singularly perturbed Fredholm integro differential equation (SPFIDE) with mixed boundary conditions. By using interpolating quadrature rules and exponential basis function, fitted second order difference scheme has been constructed on a Shishkin mesh. The stability and convergence of the difference scheme have been analyzed in the discrete maximum norm. Some numerical examples have been solved and numerical outcomes are obtained.