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Parameterized Littlewood--Paley Operators And Their Commutators On Herz Spaces With Variable Exponents, Lijuan Wang, Shuangping Tao Jan 2016

Parameterized Littlewood--Paley Operators And Their Commutators On Herz Spaces With Variable Exponents, Lijuan Wang, Shuangping Tao

Turkish Journal of Mathematics

The aim of this paper is to deal with Littlewood--Paley operators with real parameters, including the parameterized Lusin area integrals and the parameterized Littlewood--Paley $g_{\lambda}^{\ast}$-functions, and their commutators on Herz spaces with two variable exponents $p(\cdot),~q(\cdot)$. By using the properties of the Lebesgue spaces with variable exponents, the boundedness of the parameterized Littlewood--Paley operators and their commutators generated respectively by BMO function and Lipschitz function is obtained on those Herz spaces.


On The Twisted Modules For Finite Matrix Groups, Kübra Gül, Nurullah Ankaralioğlu Jan 2016

On The Twisted Modules For Finite Matrix Groups, Kübra Gül, Nurullah Ankaralioğlu

Turkish Journal of Mathematics

Suppose that $W$ is an irreducible $F_{q}G$-module of dimension $n$ $% (d^{2}


An Extension Of Cline''S Formula For A Generalized Drazin Inverse, Haifeng Lian, Qingping Zeng Jan 2016

An Extension Of Cline''S Formula For A Generalized Drazin Inverse, Haifeng Lian, Qingping Zeng

Turkish Journal of Mathematics

In this note we give an answer to a question recently posed by Zeng and Zhong, to note that Cline's formula for a generalized Drazin inverse extends to the case when $aba=aca$. Cline's formula for a pseudo Drazin inverse is also presented in this case.


Quenching Behavior Of A Semilinear Reaction-Diffusion System With Singularboundary Condition, Burhan Selçuk Jan 2016

Quenching Behavior Of A Semilinear Reaction-Diffusion System With Singularboundary Condition, Burhan Selçuk

Turkish Journal of Mathematics

In this paper, we study the quenching behavior of the solution of a semilinear reaction-diffusion system with singular boundary condition. We first get a local exisence result. Then we prove that the solution quenches only on the right boundary in finite time and the time derivative blows up at the quenching time under certain conditions. Finally, we get lower bounds and upper bounds for quenching time.


A Note On Gorenstein Projective Complexes, Bo Lu, Liu Zhongkui Jan 2016

A Note On Gorenstein Projective Complexes, Bo Lu, Liu Zhongkui

Turkish Journal of Mathematics

As we know, a complex $Q$ is projective if and only if $Q$ is exact and $\mathrm{Z}_n(Q)$ is projective in $R$-$\mathrm{Mod}$ for each $n\in\mathbb{Z}$. In this article, we show that a complex $G$ is Gorenstein projective with Hom$_R(P,G)$ and Hom$_R(G,P)$ exact for any Cartan--Eilenberg projective complex $P$ if and only if $G$ is exact and $\mathrm{Z}_n(G)$ is Gorenstein projective in $R$-$\mathrm{Mod}$ for each $n\in\mathbb{Z}$. Using the above result, a new equivalent characterization of some $\mathcal{A}$ complexes is obtained.


Fixed Point Theory In Wc--Banach Algebras, Aref Jeribi, Bilel Krichen, Bilel Mefteh Jan 2016

Fixed Point Theory In Wc--Banach Algebras, Aref Jeribi, Bilel Krichen, Bilel Mefteh

Turkish Journal of Mathematics

In this paper, we will prove some fixed point theorems for the sum and the product of nonlinear weakly sequentially continuous operators acting on a WC--Banach algebra. Our results improve and correct some recent results given by Banas and Taoudi, and extend several earlier works using the condition $(\mathcal{P})$.


Construction Of Biorthogonal Wavelet Packets On Local Fields Of Positive Characteristic, Firdous Ahmad Shah, Mohammad Younus Bhat Jan 2016

Construction Of Biorthogonal Wavelet Packets On Local Fields Of Positive Characteristic, Firdous Ahmad Shah, Mohammad Younus Bhat

Turkish Journal of Mathematics

Orthogonal wavelet packets lack symmetry, which is a much desired property in image and signal processing. The biorthogonal wavelet packets achieve symmetry where the orthogonality is replaced by biorthogonality. In the present paper, we construct biorthogonal wavelet packets on local fields of positive characteristic and investigate their properties by means of Fourier transforms. We also show how to obtain several new Riesz bases of the space $L^2(K)$ by constructing a series of subspaces of these wavelet packets. Finally, we provide algorithms for the decomposition and reconstruction using these biorthogonal wavelet packets.


Solving An Initial Boundary Value Problem On Thesemiinfinite Interval, Feri̇he Atalan, Gusein Sh. Guseinov Jan 2016

Solving An Initial Boundary Value Problem On Thesemiinfinite Interval, Feri̇he Atalan, Gusein Sh. Guseinov

Turkish Journal of Mathematics

We explore the sign properties of eigenvalues and the basis properties of eigenvectors for a special quadratic matrix polynomial and use the results obtained to solve the corresponding linear system of differential equations on the half line subject to an initial condition at $t=0$ and a condition at $t=\infty$.


The $Q$-Analogue Of The $E_{2;1}$-Transform And Its Applications, Ahmed Salem, Faruk Uçar Jan 2016

The $Q$-Analogue Of The $E_{2;1}$-Transform And Its Applications, Ahmed Salem, Faruk Uçar

Turkish Journal of Mathematics

In this paper, we introduce a new integral transform $\ _{q}\mathcal{E}_{2;1}$, which is the $q$-analogue of the $\mathcal{E}_{2;1}$-transform and can be regarded as a $\mathit{q}$-extension of the $\mathcal{E}_{2;1}$-transform. Some identities involving $~_{q}L_{2}$-transfom, $~_{q}\mathcal{L}_{2}$-transfom, and $\mathcal{P}_{q}$-transform are given. By making use of these identities and $\ _{q}\mathcal{E}_{2;1}$-transform, a new Parseval--Goldstein type theorem is obtained. Some examples are also given as an illustration of the main results presented here.


A Note On Riesz Space Valued Measures, Neşet Özkan Tan Jan 2016

A Note On Riesz Space Valued Measures, Neşet Özkan Tan

Turkish Journal of Mathematics

In this paper, some properties of Riesz space valued measures that are defined on an algebra of sets are obtained. The question of under what conditions $oba(\mathcal{F},E)$ =$a(\mathcal{F},E)$ for a given Dedekind complete Riesz space $E$ is answered under natural conditions. The outer measure, which is generated by order bounded Riesz space valued measure, is obtained and its properties are investigated. The concept of hazy convergence that is valid for real valued signed measures is extended to Riesz space valued measures. The consequences of order convergence of $f:X\rightarrow E$, which implies hazy convergence, are given.


Evaluation Of Spectrum Of 2-Periodic Tridiagonal-Sylvester Matrix, Emrah Kiliç, Talha Arikan Jan 2016

Evaluation Of Spectrum Of 2-Periodic Tridiagonal-Sylvester Matrix, Emrah Kiliç, Talha Arikan

Turkish Journal of Mathematics

The Sylvester matrix was first defined by JJ Sylvester. Some authors have studied the relationships between certain orthogonal polynomials and the determinant of the Sylvester matrix. Chu studied a generalization of the Sylvester matrix. In this paper, we introduce its $2$-periodic generalization. Then we compute its spectrum by left eigenvectors with a similarity trick.


Notes On Cotorsion Dimension Of Hopf--Galois Extensions, Xiaoyan Zhou, Min Wei Jan 2016

Notes On Cotorsion Dimension Of Hopf--Galois Extensions, Xiaoyan Zhou, Min Wei

Turkish Journal of Mathematics

Let $H$ be a finite dimensional Hopf algebra over a field $k$ and $A/B$ be a right $H$-Galois extension. In this note the relationship of cotorsion dimensions between $A$ and $B$ will be studied. We prove that $\mbox{r.cot.D}(A)\leq\mbox{r.cot.D}(B)+\mbox{l.D}(H)$. Moreover, we give some sufficient conditions for which $\mbox{r.cot.D}(A)=\mbox{r.cot.D}(B)$. As applications, we obtain some results about cotorsion dimension of the smash product.


Shellability Of Simplicial Complexes And Simplicial Complexes With The Free Vertex Property, Guangjun Zhu Jan 2016

Shellability Of Simplicial Complexes And Simplicial Complexes With The Free Vertex Property, Guangjun Zhu

Turkish Journal of Mathematics

To a simplicial complex $\Delta$, we associate a square-free monomial ideal $\mathcal{F}(\Delta)$ in the polynomial ring generated by its facet over a field. Furthermore, we could consider $\mathcal{F}(\Delta)$ as the Stanley--Reisner ideal of another simplicial complex $\delta_{N}(\mathcal{F}(\Delta))$ from facet ideal theory and Stanley--Reisner theory. In this paper, we determine what families of simplicial complexes $\Delta$ have the property that their Stanley--Reisner complexes $\delta_{N}(\mathcal{F}(\Delta))$ are shellable. Furthermore, we show that the simplicial complex with the free vertex property is sequentially Cohen--Macaulay. This result gives a new proof for a result of Faridi on the sequentially Cohen--Macaulayness of simplicial forests.


Zero-Divisor Graph Of Matrix Rings And Hurwitz Rings, Ci̇hat Abdi̇oğlu Jan 2016

Zero-Divisor Graph Of Matrix Rings And Hurwitz Rings, Ci̇hat Abdi̇oğlu

Turkish Journal of Mathematics

Let $R$ be ring a with identity $1\neq 0$, $S_n(R)$ be a subring of the ring $T_n(R)$ of $n\times n$ upper triangular matrices over $R$, and $H_n(R)$ be the ring defined in the next section using $HR$, the ring of the Hurwitz series over $R$. In this paper, we introduce the zero-divisor graph $\overset{\rightarrow}{\Gamma}(S_n(R))$ and its underlying undirected graph $\Gamma(S_n(R))$ of $S_n(R)$. We give some basic graph theory properties of $\overset{\rightarrow}{\Gamma}(S_n(R))$. Moreover, we obtain some results of the zero-divisor directed graph of $\overset{\rightarrow}{\Gamma}(H_n(R))$.


Rectifying Curves In The $N$-Dimensional Euclidean Space, Stijn Cambie, Wendy Goemans, Iris Van Den Bussche Jan 2016

Rectifying Curves In The $N$-Dimensional Euclidean Space, Stijn Cambie, Wendy Goemans, Iris Van Den Bussche

Turkish Journal of Mathematics

In this article, we study the so-called rectifying curves in an arbitrary dimensional Euclidean space. A curve is said to be a rectifying curve if, in all points of the curve, the orthogonal complement of its normal vector contains a fixed point. If this fixed point is chosen to be the origin, then this condition is equivalent to saying that the position vector of the curve in every point lies in the orthogonal complement of its normal vector. Here we characterize rectifying curves in the $n$-dimensional Euclidean space in different ways: using conditions on their curvatures, with an expression for …


Isometric $N$-Jordan Weighted Shift Operators, Saeed Yarmahmoodi, Karim Hedayatian Jan 2016

Isometric $N$-Jordan Weighted Shift Operators, Saeed Yarmahmoodi, Karim Hedayatian

Turkish Journal of Mathematics

A bounded linear operator $T$ on a Hilbert space is an isometric $N$-Jordan operator if it can be written as $A+Q$, where $A$ is an isometry and $Q$ is a nilpotent of order $N$ such that $AQ= QA$. In this paper, we will show that the only isometric $N$-Jordan weighted shift operators are isometries. This answers a question recently raised.


Regularity And Projective Dimension Of Some Class Of Well-Covered Graphs, Esfandiyar Lashani, Ali Soleyman Jahan Jan 2016

Regularity And Projective Dimension Of Some Class Of Well-Covered Graphs, Esfandiyar Lashani, Ali Soleyman Jahan

Turkish Journal of Mathematics

In this paper we study the Castelnuovo--Mumford regularity of an edge ideal associated with a graph in a special class of well-covered graphs. We show that if $G$ belongs to the class $\mathcal {SQ}$, then the Castelnuovo-Mumford regularity of $R/I(G)$ will be equal to induced matching number of $G$. For this class of graphs we also compute the projective dimension of the ring $R/I(G)$. As a corollary we describe these invariants in well-covered forests, well-covered chordal graphs, Cohen-Macaulay Cameron-Walker graphs, and simplicial graphs.


$Q$-Riordan Array For $Q$-Pascal Matrix And Its Inverse Matrix, Nai̇m Tuğlu, Fatma Yeşi̇l, Maciej Dziemianczuk, E. Gökçen Koçer Jan 2016

$Q$-Riordan Array For $Q$-Pascal Matrix And Its Inverse Matrix, Nai̇m Tuğlu, Fatma Yeşi̇l, Maciej Dziemianczuk, E. Gökçen Koçer

Turkish Journal of Mathematics

In this paper, we prove the $q$-analogue of the fundamental theorem of Riordan arrays. In particular, by defining two new binary operations $\ast_{q} $ and $\ast _{1/q}$, we obtain a $q$-analogue of the Riordan representation of the $q$-Pascal matrix. In addition, by aid of the $q$-Lagrange expansion formula we get $q$-Riordan representation for its inverse matrix.


On A Factorization Of Operators On Finite Dimensional Hilbert Spaces, Jiawei Luo, Juexian Li, Geng Tian Jan 2016

On A Factorization Of Operators On Finite Dimensional Hilbert Spaces, Jiawei Luo, Juexian Li, Geng Tian

Turkish Journal of Mathematics

As is well known, for any operator $T$ on a complex separable Hilbert space, $T$ has the polar decomposition $T=U T $, where $U$ is a partial isometry and $ T $ is the nonnegative operator $(T^*T)^{\frac{1}{2}}$. In 2014, Tian et al. proved that on a complex separable infinite dimensional Hilbert space, any operator admits a polar decomposition in a strongly irreducible sense. More precisely, for any operator $T$ and any $\varepsilon>0$, there exists a decomposition $T=(U+K)S$, where $U$ is a partial isometry, $K$ is a compact operator with $ K


High-Order Uniformly Convergent Method For Nonlinear Singularly Perturbed Delay Differential Equations With Small Shifts, Abdelhay Salama, Dirhem Al-Amery Jan 2016

High-Order Uniformly Convergent Method For Nonlinear Singularly Perturbed Delay Differential Equations With Small Shifts, Abdelhay Salama, Dirhem Al-Amery

Turkish Journal of Mathematics

In this paper, we propose and analyze a high-order uniform method for solving boundary value problems (BVPs) for singularly perturbed nonlinear delay differential equations with small shifts (delay and advance). Such types of BVPs play an important role in the modeling of various real life phenomena, such as the variational problem in control theory and in the determination of the expected time for the generation of action potentials in nerve cells. To obtain parameter-uniform convergence, the present method is constructed on a piecewise-uniform Shishkin mesh. The error estimate is discussed and it is shown that the method is uniformly convergent …


Pseudospectral Operational Matrix For Numerical Solution Of Single And Multiterm Time Fractional Diffusion Equation, Saeid Gholami, Esmail Babolian, Mohammad Javidi Jan 2016

Pseudospectral Operational Matrix For Numerical Solution Of Single And Multiterm Time Fractional Diffusion Equation, Saeid Gholami, Esmail Babolian, Mohammad Javidi

Turkish Journal of Mathematics

This paper presents a new numerical approach to solve single and multiterm time fractional diffusion equations. In this work, the space dimension is discretized to the Gauss$-$Lobatto points. We use the normalized Grunwald approximation for the time dimension and a pseudospectral successive integration matrix for the space dimension. This approach shows that with fewer numbers of points, we can approximate the solution with more accuracy. Some examples with numerical results in tables and figures displayed.


On Generalized Ostrowski-Type Inequalities For Functions Whose First Derivatives Absolute Values Are Convex, Hüseyi̇n Budak, Mehmet Zeki̇ Sarikaya Jan 2016

On Generalized Ostrowski-Type Inequalities For Functions Whose First Derivatives Absolute Values Are Convex, Hüseyi̇n Budak, Mehmet Zeki̇ Sarikaya

Turkish Journal of Mathematics

In this paper, we establish some generalized Ostrowski-type inequalities for functions whose first derivatives absolute values are convex.


Some Properties Of Concave Operators, Lotfollah Karimi, Masoumeh Faghih Ahmadi, Karim Hedayatian Jan 2016

Some Properties Of Concave Operators, Lotfollah Karimi, Masoumeh Faghih Ahmadi, Karim Hedayatian

Turkish Journal of Mathematics

A bounded linear operator $T$ on a Hilbert space $\mathcal{H}$ is concave if, for each $x\in\mathcal{H}$, $\ T^2x\ ^2-2\ Tx\ ^2 +\ x\ ^2 \leq 0$. In this paper, it is shown that if $T$ is a concave operator then so is every power of $T$. Moreover, we investigate the concavity of shift operators. Furthermore, we obtain necessary and sufficient conditions for N-supercyclicity of co-concave operators. Finally, we establish necessary and sufficient conditions for the left and right multiplications to be concave on the Hilbert-Schmidt class.


On Hermite-Hadamard Type Inequalities Via Generalized Fractional Integrals, Mohamed Jleli, Donal O'Regan, Bessem Samet Jan 2016

On Hermite-Hadamard Type Inequalities Via Generalized Fractional Integrals, Mohamed Jleli, Donal O'Regan, Bessem Samet

Turkish Journal of Mathematics

New Hermite-Hadamard type inequalities are obtained for convex functions via generalized fractional integrals. The results presented here are generalizations of those obtained in earlier works.


Mixed Modulus Of Continuity In The Lebesgue Spaces With Muckenhouptweights And Their Properties, Ramazan Akgün Jan 2016

Mixed Modulus Of Continuity In The Lebesgue Spaces With Muckenhouptweights And Their Properties, Ramazan Akgün

Turkish Journal of Mathematics

Main properties of the mixed modulus of continuity in the Lebesgue spaces with Muckenhoupt weights are investigated. We use the mixed modulus of continuity to obtain Potapov type direct and inverse estimates of angular trigonometric approximation of functions in these spaces. We prove an equivalence between the mixed modulus of continuity and K -functional and realization functional.


Structural Stability Analysis Of Solutions To The Initial Boundary Value Problem For A Nonlinear Strongly Damped Wave Equation, Şevket Gür, İpek Güleç Jan 2016

Structural Stability Analysis Of Solutions To The Initial Boundary Value Problem For A Nonlinear Strongly Damped Wave Equation, Şevket Gür, İpek Güleç

Turkish Journal of Mathematics

In this paper the initial-boundary value problem for a nonlinear strongly damped wave equation is considered. We analyze the structural stability of solutions of the nonlinear strongly damped wave equation with coefficients from $H^1(\Omega)$.


Perturbational Self-Similar Solutions For The 2-Component Degasperis-Procesi System Via A Characteristic Method, Hongli An, Ka-Luen Cheung, Manwai Yuen Jan 2016

Perturbational Self-Similar Solutions For The 2-Component Degasperis-Procesi System Via A Characteristic Method, Hongli An, Ka-Luen Cheung, Manwai Yuen

Turkish Journal of Mathematics

In this paper, the two-component Degasperis-Procesi system arising in shallow water theory is investigated. By using a special transformation and the characteristic method, a class of perturbational self-similar solutions is constructed. Such solutions are not only more general than those obtained by Yuen in 2011, but also they may have potential applications in the modeling of tsunamis. In addition, the method proposed can be extended to other mathematical physics models like the two-component Camassa-Holm equations.


Some Normality Criteria, Gopal Datt, Sanjay Kumar Jan 2016

Some Normality Criteria, Gopal Datt, Sanjay Kumar

Turkish Journal of Mathematics

In this article, we prove some normality criteria for a family of meromorphic functions, which involves sharing of a nonzero value by certain differential monomials generated by the members of the family. These results generalize some of the results of Schwick.


Invariant Structures And Gauge Transformation Of Almost Contact Metric Manifolds, Morteza Mirmohammad Rezaii, Mehrnoosh Zandi Jan 2016

Invariant Structures And Gauge Transformation Of Almost Contact Metric Manifolds, Morteza Mirmohammad Rezaii, Mehrnoosh Zandi

Turkish Journal of Mathematics

In this paper, conditions for K-contact, Sasakian, and cosymplectic structures to be invariant under gauge transformation are found. Moreover, the same question is studied for 3-Sasakian, 3-almost contact, and 3-cosymplectic manifolds. Finally, it is shown that a slant submanifold of an almost contact metric manifold is invariant by gauge transformation.


Approximation Of $B$-Continuous And $B$-Differentiable Functions By Gbs Operators Of $Q$-Bernstein-Schurer-Stancu Type, Manjari Sidharth, Nurhayat İspi̇r, Purshottam Narain Agrawal Jan 2016

Approximation Of $B$-Continuous And $B$-Differentiable Functions By Gbs Operators Of $Q$-Bernstein-Schurer-Stancu Type, Manjari Sidharth, Nurhayat İspi̇r, Purshottam Narain Agrawal

Turkish Journal of Mathematics

B&acaron;rbosu and Muraru (2015) introduced the bivariate generalization of the $q$-Bernstein-Schurer-Stancu operators and constructed a GBS operator of $q$-Bernstein-Schurer-Stancu type. The concern of this paper is to obtain the rate of convergence in terms of the partial and complete modulus of continuity and the degree of approximation by means of Lipschitz-type class for the bivariate operators. In the last section we estimate the degree of approximation by means of Lipschitz class function and the rate of convergence with the help of mixed modulus of smoothness for the GBS operator of $q$-Bernstein-Schurer-Stancu type. Furthermore, we show comparisons by some illustrative graphics …