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The Australian Journal of Mathematical Analysis and Applications
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Paper's Title:
Applications of Von Neumann Algebras to Rigidity Problems of (2-Step) Riemannian (Nil-)Manifolds
Author(s):
Atefeh Hasan-Zadeh and Hamid-Reza Fanai
DFouman Faculty of Engineering,
College of Engineering, University of Tehran,
Iran.
E-mail: hasanzadeh.a@ut.ac.ir
Department of Mathematical Sciences,
Sharif University of Technology,
Iran
E-mail: fanai@sharif.edu
Abstract:
In this paper, basic notions of von Neumann algebra and its direct analogues in the realm of groupoids and measure spaces have been considered. By recovering the action of a locally compact Lie group from a crossed product of a von Neumann algebra, other proof of one of a geometric propositions of O'Neil and an extension of it has been proposed. Also, using the advanced exploration of nilmanifolds in measure spaces and their corresponding automorphisms (Lie algebraic derivations) a different proof of an analytic theorem of Gordon and Mao has been attained. These two propositions are of the most important ones for rigidity problems of Riemannian manifolds especially 2-step nilmanifolds.
Paper's Title:
Generalized Von Neumann-Jordan Constant for Morrey Spaces and Small Morrey Spaces
Author(s):
H. Rahman and H. Gunawan
Department of Mathematics,
Islamic State University Maulana Malik Ibrahim Malang,
Jalan Gajayana No.50,
Indonesia.
E-mail: hairur@mat.uin-malang.ac.id
Analysis and Geometry Group,
Faculty of Mathematics and Natural Sciences,
Bandung Institute of Technology, Bandung 40132,
Indonesia.
E-mail: hgunawan@math.itb.ac.id
URL:
http://personal.fmipa.itb.ac.id/hgunawan/
Abstract:
In this paper we calculate some geometric constants for Morrey spaces and small Morrey spaces, namely generalized Von Neumann-Jordan constant, modified Von Neumann-Jordan constants, and Zbaganu constant. All these constants measure the uniformly nonsquareness of the spaces. We obtain that their values are the same as the value of Von Neumann-Jordan constant for Morrey spaces and small Morrey spaces.
Paper's Title:
Existence of Optimal Parameters for Damped Sine-Gordon Equation with Variable Diffusion Coefficient and Neumann Boundary Conditions
Author(s):
N. Thapa
Department of Mathematical Sciences,
Cameron University,
2800 West Gore Blvd,
73505 Lawton, Oklahoma,
USA.
E-mail: nthapa@cameron.edu
URL: http://www.cameron.edu/~nthapa/
Abstract:
The parameter identification problem for sine-Gordon equation is of a major interests among mathematicians and scientists.\ In this work we the consider sine-Gordon equation with variable diffusion coefficient and Neumann boundary data. We show the existence and uniqueness of weak solution for sine-Gordon equation. Then we show that the weak solution continuously depends on parameters. Finally we show the existence of optimal set of parameters.
Paper's Title:
Product Formulas Involving Gauss Hypergeometric Functions
Author(s):
Edward Neuman
Department of Mathematics, Mailcode 4408,
Southern Illinois University,
1245 Lincoln Drive,
Carbondale, IL 62901,
USA.
edneuman@math.siu.edu
URL: http://www.math.siu.edu/neuman/personal.html
Abstract:
New formulas for a product of two Gauss hypergeometric functions are derived.
Applications to special functions, with emphasis on Jacobi polynomials, Jacobi functions, and Bessel functions of the first kind, are included.
Most of the results are obtained with the aid of the double Dirichlet average of a univariate function.
Paper's Title:
Two Geometric Constants Related to Isosceles Orthogonality on Banach Space
Author(s):
Huayou Xie, Qi Liu and Yongjin Li
Department of Mathematics,
Sun Yat-sen University,
Guangzhou, 510275,
P. R. China.
E-mail: xiehy33@mail2.sysu.edu.cn
Department of Mathematics,
Sun Yat-sen University,
Guangzhou, 510275,
P. R. China.
E-mail: liuq325@mail2.sysu.edu.cn
Department of Mathematics,
Sun Yat-sen University,
Guangzhou, 510275,
P. R. China.
E-mail: stslyj@mail.sysu.edu.cn
Abstract:
In this paper, we introduce new geometric constant C(X,ai,bi,ci,2) to measure the difference between isosceles orthogonality and special Carlsson orthogonalities. At the same time, we also present the geometric constant C(X,ai,bi,ci), which is a generalization of the rectangular constant proposed by Joly. According to the inequality on isosceles orthogonality, we give the boundary characterization of these geometric constants. Then the relationship between these geometric constants and uniformly non-square property can also be discussed. Furthermore, we show that there is a close relationship between these geometric constants and some important geometric constants.
Paper's Title:
On Stan Ulam and his Mathematics
Author(s):
Krzysztof Ciesielski and Themistocles M. Rassias
Mathematics Institute, Jagiellonian University,
Abstract:
In this note we give a glimpse of the curriculum vitae of Stan Ulam, his personality and some of the mathematics he was involved in.
Paper's Title:
Solving Two Point Boundary Value Problems by Modified Sumudu Transform Homotopy Perturbation Method
Author(s):
Asem AL Nemrat and Zarita Zainuddin
School of Mathematical Sciences,
Universiti Sains Malaysia,
11800 Penang,
Malaysia.
E-mail: alnemrata@yahoo.com
zarita@usm.my
Abstract:
This paper considers a combined form of the Sumudu transform with the modified homotopy perturbation method (MHPM) to find approximate and analytical solutions for nonlinear two point boundary value problems. This method is called the modified Sumudu transform homotopy perturbation method (MSTHPM). The suggested technique avoids the round-off errors and finds the solution without any restrictive assumptions or discretization. We will introduce an appropriate initial approximation and furthermore, the residual error will be canceled in some points of the interval (RECP). Only a first order approximation of MSTHPM will be required, as compared to STHPM, which needs more iterations for the same cases of study. After comparing figures between approximate, MSTHPM, STHPM and numerical solutions, it is found through the solutions we have obtained that they are highly accurate, indicating that the MSTHPM is very effective, simple and can be used to solve other types of nonlinear boundary value problems (BVPs).
Paper's Title:
Some Moduli and Inequalities Related to Birkhoff Orthogonality in Banach Spaces
Author(s):
Dandan Du and Yongjin Li
Department of Mathematics,
Sun Yat-sen University,
Guangzhou, 510275,
P.R. China.
E-mail: dudd5@mail2.sysu.edu.cn
Department of Mathematics,
Sun Yat-sen University,
Guangzhou, 510275,
P.R. China.
E-mail: stslyj@mail.sysu.edu.cn
Abstract:
In this paper, we shall consider two new constants δB(X) and ρB(X), which are the modulus of convexity and the modulus of smoothness related to Birkhoff orthogonality, respectively. The connections between these two constants and other well-known constants are established by some equalities and inequalities. Meanwhile, we obtain two characterizations of Hilbert spaces in terms of these two constants, study the relationships between the constants δB(X), ρB(X) and the fixed point property for nonexpansive mappings. Furthermore, we also give a characterization of the Radon plane with affine regular hexagonal unit sphere.
Paper's Title:
Integer Sums of Powers of Trigonometric Functions (MOD p), for prime p
Author(s):
G. J. Tee
Department of Mathematics, University of Auckland,
Auckland,
New Zealand
tee@math.auckland.ac.nz
Abstract:
Many multi--parameter families of congruences (mod p) are found for integer
sums of
qth powers of the trigonometric functions over various sets of equidistant
arguments, where
p is any prime factor of q. Those congruences provide sensitive
tests for the accuracy
of software for evaluating trigonometric functions to high precision.
Paper's Title:
Real Interpolation Methods and Quasilogarithmic Operators
Author(s):
Ming Fan
School of Industrial Technology and Management,
Dalarna University, 781 88 Borlänge, Sweden
fmi@du.se
URL: http://users.du.se/~fmi
Abstract:
The purpose of this paper is to deal with nonlinear quasilogarithmic operators, which possesses the uniformly bounded commutator property on various interpolation spaces in the sense of Brudnyi-Krugljak associated with the quasi-power parameter spaces. The duality, and the domain and range spaces of these operators are under consideration. Some known inequalities for the Lebesgue integration spaces and the trace classes are carried over to the non-commutative symmetric spaces of measurable operators affiliated with a semi-finite von Neumann algebra.
Paper's Title:
Expected Utility with Subjective Events
Author(s):
Jacob Gyntelberg and Frank Hansen
Bank for International Settlements,
Basel,
Switzerland
Tohoku University, Institute for International Education,
Sendai,
Japan
Abstract:
We provide a new theory of expected utility with subjective events modeled by a lattice of projections. This approach allows us to capture the notion of a ``small world'' as a context dependent or local state space embedded into a subjective set of events, the ``grand world''. For each situation the decision makers' subjective ``small world'' reflects the events perceived to be relevant for the act under consideration. The subjective set of events need not be representable by a classical state space. Maintaining preference axioms similar in spirit to the classical axioms, we obtain an expected utility representation which is consistent across local state spaces and separates subjective probability and utility. An added benefit is that this alternative expected utility representation allows for an intuitive distinction between risk and uncertainty.
Paper's Title:
Stability of the D-Bar Reconstruction Method for Complex Conductivities
Author(s):
1S. El Kontar, 1T. El Arwadi, 1H. Chrayteh, 2J.-M. Sac-Épée
1Department of Mathematics and
Computer Science,
Faculty of Science, Beirut Arab University,
P.O. Box: 11-5020, Beirut,
Lebanon.
E-mail: srs915@student.bau.edu.lb
2Institut Élie Cartan de
Lorraine,
Université de Lorraine - Metz,
France.
Abstract:
In 2000, Francini solved the inverse conductivity problem for twice-differentiable conductivities and permittivities. This solution was considered to be the first approach using D-bar methods with complex conductivities. In 2012, based on Francini's work, Hamilton introduced a reconstruction method of the conductivity distribution with complex values. The method consists of six steps. A voltage potential is applied on the boundary. Solving a D-Bar equation gives the complex conductivity. In this paper, the stability of the D-Bar equation is studied via two approximations, texp and tB, for the scattering transform. The study is based on rewriting the reconstruction method in terms of continuous operators. The conductivity is considered to be non smooth.
Paper's Title:
Mass Transportation Approach For Parabolic P-Biharmonic Equations
Author(s):
A. Soglo, K. W. Houedanou, J. Adetola
Institut de Mathematiques et de Sciences
Physiques (IMSP)
Universite d'Abomey-Calavi,
Rep. of Benin
E-mail: ambroiso.soglo@gmail.com
Departement de Mathematiques
Faculte des Sciences et Techniques (FAST)
Universite d'Abomey-Calavi,
Rep. of Benin
E-mail: khouedanou@yahoo.fr
Universite Nationale des Sciences, Technologie, Ingenierie et
Mathematiques (UNSTIM,
Abomey,
Rep. of Benin
E-mail: adetolajamal58@yahoo.com
Abstract:
In this paper, we propose a mass transportation method to solving a parabolic p-biharmonic equations, which generalized the Cahn-Hilliard (CH) equations in RN, N∈N*. By using a time-step optimal approximation in the appropriate Wasserstein space, we define an approximate weak solution which converges to the exact solution of the problem. We also show that the solution under certain conditions may be unique. Therefore, we study the asymptotic behavior of the solution of the parabolic p-biharmonic problem.
Paper's Title:
A general theory of decision making
Author(s):
Frank Hansen
Department of Economics,
University of Copenhagen,
Studiestraede 6, DK-1455 Copenhagen K
Denmark
Frank.Hansen@econ.ku.dk
URL: http://www.econ.ku.dk/okofh
Abstract:
We formulate a general theory of decision making based on a lattice of observable events, and we exhibit
a large class of representations called the general model. Some of the representations are equivalent to
the so called standard model in which observable events are modelled by
an algebra of measurable subsets of a state space, while others are not compatible with such a description.
We show that the general model collapses to the standard model, if and only if an additional axiom
is satisfied. We argue that this axiom is not very
natural and thus assert that the standard model may not be general enough to model all relevant
phenomena in economics. Using the general model we are
(as opposed to Schmeidler [16]) able to rationalize Ellsberg's paradox
without the introduction of non-additive measures.
Paper's Title:
Existence of Solutions for Third Order Nonlinear Boundary Value Problems
Author(s):
Yue Hu and Zuodong Yang
School of Mathematics and Computer Science, Nanjing Normal University, Jiangsu Nanjing 210097,
China.
huu3y2@163.com
College of Zhongbei, Nanjing Normal University, Jiangsu Nanjing 210046,
China.
zdyang_jin@263.net
yangzuodong@njnu.edu.cn
Abstract:
In this paper, the existence of solution for a class of third order quasilinear ordinary differential equations with nonlinear boundary value problems
(Φp(u"))'=f(t,u,u',u"), u(0)=A, u'(0)=B, R(u'(1),u"(1))=0
is established. The results are obtained by using upper and lower solution methods.
Paper's Title:
Positive Periodic Solutions for
Second-Order Differential Equations with Generalized Neutral Operator
Author(s):
Wing-Sum Cheung, Jingli Ren and Weiwei Han
Department of Mathematics,
The University of Hong Kong
Pokfulam
Road,
Hong Kong
Department of Mathematics, Zhengzhou University
Zhengzhou 450001,
P.R. China
wscheung@hkucc.hku.hk
renjl@zzu.edu.cn
Abstract:
By some analysis of the neutral operator
and an application of the fixed-point
index theorem, we obtain sufficient conditions for the existence,
multiplicity and nonexistence of periodic solutions to a second-order
differential equation with the prescribed neutral operator, which improve
and extend some recent results of Lu-Ge, Wu-Wang, and Zhang. An example is
given to illustrate our results. Moreover, the analysis of the generalized
neutral operator will be helpful for other types of differential equations.
Paper's Title:
A Coincidence Theorem for Two Kakutani Maps
Author(s):
Mircea Balaj
Department of Mathematics,
University of Oradea,
410087, Oradea,
Romania.
mbalaj@uoradea.ro
Abstract:
In this paper we prove the following theorem: Let X be a nonempty compact convex set in a locally convex Hausdorff topological vector space, D be the set of its extremal points and F,T: X―◦X two Kakutani maps; if for each nonempty finite subset A of D and for any x ∈ coA, F (x) ∩ coA ≠ Ř, then F and T have a coincidence point. The proof of this theorem is given first in the case when X is a simplex, then when X is a polytope and finally in the general case. Several reformulations of this result are given in the last part of the paper.
Paper's Title:
Scope of the Logarithmic Mean
Author(s):
Murali Rao and Agnish Dey
Department of Mathematics,
University of Florida,
1400 Stadium Road, Gainesville,
Florida 32611,
U. S. A.
E-mail: mrao@ufl.edu
URL: http://people.clas.ufl.edu/mrao
E-mail: agnish@ufl.edu
URL: http://people.clas.ufl.edu/agnish
Abstract:
A number a is between two numbers x and y if and only if a is a convex combination of x and y, in other words, it is a "weighted mean" of x and y. Geometric mean, arithmetic mean are well known examples of these "means". Of more recent vintage is the logarithmic mean which has been considered in many articles in the literature. In this note, we first discuss some of its properties. Then we shall introduce the L function and explore the inverse of this function and its connection with the Lambert's Omega function.
Paper's Title:
Higher Order Accurate Compact Schemes for Time Dependent Linear and Nonlinear Convection-Diffusion Equations
Author(s):
S. Thomas, Gopika P.B. and S. K. Nadupuri
Department of Mathematics
National Institute of Technology Calicut
Kerala
673601
India.
E-mail:
sobinputhiyaveettil@gmail.com
pbgopika@gmail.com nsk@nitc.ac.in
Abstract:
The primary objective of this work is to study higher order compact finite difference schemes for finding the numerical solution of convection-diffusion equations which are widely used in engineering applications. The first part of this work is concerned with a higher order exponential scheme for solving unsteady one dimensional linear convection-diffusion equation. The scheme is set up with a fourth order compact exponential discretization for space and cubic $C^1$-spline collocation method for time. The scheme achieves fourth order accuracy in both temporal and spatial variables and is proved to be unconditionally stable. The second part explores the utility of a sixth order compact finite difference scheme in space and Huta's improved sixth order Runge-Kutta scheme in time combined to find the numerical solution of one dimensional nonlinear convection-diffusion equations. Numerical experiments are carried out with Burgers' equation to demonstrate the accuracy of the new scheme which is sixth order in both space and time. Also a sixth order in space predictor-corrector method is proposed. A comparative study is performed of the proposed schemes with existing predictor-corrector method. The investigation of computational order of convergence is presented.
Paper's Title:
Viability
Theory And Differential Lanchester Type Models For Combat.
Differential Systems.
Author(s):
G. Isac and A. Gosselin
Department Of
Mathematics, Royal Military College Of Canada,
P.O. Box 17000, Stn Forces, Kingston,
Ontario, Canada K7k 7b4
isac-g@rmc.ca
gosselin-a@rmc.ca
URL:
http://www.rmc.ca/academic/math_cs/isac/index_e.html
URL:
http://www.rmc.ca/academic/math_cs/gosselin/index_e.html
Abstract:
In 1914, F.W. Lanchester proposed several mathematical models based on differential equations to describe combat situations [34]. Since then, his work has been extensively modified to represent a variety of competitions including entire wars. Differential Lanchester type models have been studied from many angles by many authors in hundreds of papers and reports. Lanchester type models are used in the planning of optimal strategies, supply and tactics. In this paper, we will show how these models can be studied from a viability theory stand point. We will introduce the notion of winning cone and show that it is a viable cone for these models. In the last part of our paper we will use the viability theory of differential equations to study Lanchester type models from the optimal theory point of view.
Paper's Title:
A Different Proof for the non-Existence of Hilbert-Schmidt Hankel Operators with
Anti-Holomorphic Symbols on the Bergman Space
Author(s):
Georg Schneider
Universität Wien, Brünnerstr. 72 A-1210 Wien,
Austria.
georg.schneider@univie.ac.at
URL: http://www.univie.ac.at/bwl/cont/mitarbeiter/schneider.htm
Abstract:
We show that there are no (non-trivial) Hilbert-Schmidt Hankel
operators with anti-holomorphic symbols on the Bergman space of
the unit-ball B2(Bl) for l≥2. The result dates back to
[6]. However, we give a different proof. The methodology can
be easily applied to other more general settings. Especially, as
indicated in the section containing generalizations, the new
methodology allows to prove some robustness results for existing
ones.
Paper's Title:
Stability of a Mixed Additive, Quadratic and Cubic Functional Equation In Quasi-Banach Spaces
Author(s):
A. Najati and F. Moradlou
Department of Mathematics, Faculty of Sciences,
University of Mohaghegh Ardabili, Ardabil,
Iran
a.nejati@yahoo.com
Faculty of Mathematical Sciences,
University of Tabriz, Tabriz,
Iran
moradlou@tabrizu.ac.ir
Abstract:
In this paper we establish the general solution of a mixed additive,
quadratic and cubic functional equation and investigate the
Hyers--Ulam--Rassias stability of this equation in quasi-Banach
spaces. The concept of Hyers-Ulam-Rassias stability originated from
Th. M. Rassias' stability theorem that appeared in his paper: On the
stability of the linear mapping in Banach spaces, Proc. Amer. Math.
Soc. 72 (1978), 297--300.
Paper's Title:
Trapping of Water Waves By Underwater Ridges
Author(s):
1A. M. Marin, 1R. D. Ortiz and 2J. A. Rodriguez-Ceballos.
1Facultad de Ciencias Exactas y Naturales
Universidad de Cartagena
Sede Piedra de Bolivar, Avenida del Consulado
Cartagena de Indias, Bolivar,
Colombia.
2Instituto Tecnológico de
Morelia Facultad de Ciencias Fisico Matematicas
Universidad Michoacana
Tecnológico
1500, Col. Lomas de Santiaguito Edificio Be ,
Ciudad Universitaria,
58120 Morelia, Michoacan,
Mexico.
amarinr@unicartagena.edu.co,
ortizo@unicartagena.edu.co.
URL: www.unicartagena.edu.co.
Abstract:
As is well-known, underwater ridges and
submerged horizontal cylinders can serve as waveguides for surface water waves.
For large values of the wavenumber in the direction of the ridge, there is only
one trapped wave (this was proved in Bonnet & Joly (1993, SIAM J. Appl. Math.
53, pp 1507-1550)).
We construct the asymptotics of these trapped waves and their frequencies at
high frequency by means of reducing the initial problem to a pair of boundary
integral equations and then by applying the method of Zhevandrov & Merzon (2003,
AMS Transl. (2) 208, pp 235-284), in order to solve
them.
Paper's Title:
To a Banach *-algebra in a Semipartial Dynamical System
Author(s):
Bahman Tabatabaie Shourijeh and Seyed Mostafa Zebarjad
Department of Mathematics,
College of Sciences,
Shiraz University, Shiraz 71454,
Iran.
E-mail:
tabataba@math.susc.ac.ir
zebarjad@mail.yu.ac.ir
URL:
http://research.shirazu.ac.ir/faculty/More.asp?ID=207
Abstract:
By a partial dynamical system, we mean a triple containing a C*-algebra A, a discrete group G and a partial action of G on A. There are two C*--algebras associated to a given partial dynamical system. These are nothing but the certain C*-completions of a Banach *-algebra. In constructing such a Banach *-algebra, usually, a tedious limit process is used to apply. In this paper, we prove some theorems in this context without any limit process.
Paper's Title:
Iterative Algorithm for Split Generalized Mixed Equilibrium Problem Involving Relaxed Monotone Mappings in Real Hilbert Spaces
Author(s):
1U.A. Osisiogu, F.L. Adum, and 2C. Izuchukwu
1Department of Mathematics and
Computer Science,
Ebonyi State University, Abakaliki,
Nigeria.
E-mail: uosisiogu@gmail.com,
adumson2@yahoo.com
2School of Mathematics,
Statistics and Computer Science,
University of KwaZulu-Natal, Durban,
South Africa.
E-mail: izuchukwuc@ukzn.ac.za,
izuchukwu_c@yahoo.com
Abstract:
The main purpose of this paper is to introduce a certain class of split generalized mixed equilibrium problem involving relaxed monotone mappings. To solve our proposed problem, we introduce an iterative algorithm and obtain its strong convergence to a solution of the split generalized mixed equilibrium problems in Hilbert spaces. As special cases of the proposed problem, we studied the proximal split feasibility problem and variational inclusion problem.
Paper's Title:
The Jacobson Density Theorem for Non-Commutative Ordered Banach
Algebras
Author(s):
Kelvin Muzundu
University of Zambia,
Deparment of Mathematics and Statistics,
P.O. Box 32379, Lusaka,
Zambia.
E-mail: kmzundu@gmail.com
Abstract:
The Jacobson density theorem for general non-commutative Banach algebras states as follows: Let π be a continuous, irreducible representation of a non-commutative Banach algebra A on a Banach space X. If x1,x2,...,xn are linearly independent in X and if y1,y2,...,yn are in X, then there exists an a∈ A such that π(a)xi=yi for i=1,2,...,n. By considering ordered Banach algebras A and ordered Banach spaces X, we shall establish an order-theoretic version of the Jacobson density theorem.
Paper's Title:
Analysis of a Frictional Contact Problem for Viscoelastic Piezoelectric Materials
Author(s):
Meziane Said Ameur, Tedjani Hadj Ammar and Laid Maiza
Departement of Mathematics,
El Oued University,
P.O. Box 789, 39000 El Oued,
Algeria.
E-mail:
said-ameur-meziane@univ-eloued.dz
Departement of Mathematics,
El Oued University,
P.O. Box 789, 39000 El Oued,
Algeria.
E-mail:
hadjammar-tedjani@univ-eloued.dz
Department of Mathematics,
Kasdi Merbah University,
30000 Ouargla,
Algeria.
E-mail: maiza.laid@univ-ouargla.dz
Abstract:
In this paper, we consider a mathematical model that describes the quasi-static process of contact between two thermo-electro-viscoelastic bodies with damage and adhesion. The damage of the materials caused by elastic deformations. The contact is frictional and modeled with a normal compliance condition involving adhesion effect of contact surfaces. Evolution of the bonding field is described by a first order differential equation. We derive variational formulation for the model and prove an existence and uniqueness result of the weak solution. The proof is based on arguments of evolutionary variational inequalities, parabolic inequalities, differential equations, and fixed point theorem.
Paper's Title:
Several Applications of a Local Non-convex Young-type Inequality
Author(s):
Loredana Ciurdariu, Sorin Lugojan
Department of Mathematics,
"Politehnica" University of Timisoara,
P-ta. Victoriei, No.2, 300006-Timisoara,
Romania.
E-mail: ltirtirau87@yahoo.com
Abstract:
A local version of the Young inequality for positive numbers is used in order to deduce some inequalities about determinants and norms for real quadratic matrices and norms of positive operators on complex Hilbert spaces.
Paper's Title:
Existence and Approximation of Traveling Wavefronts for the Diffusive Mackey-Glass Equation
Author(s):
C. Ramirez-Carrasco and J. Molina-Garay
Facultad de Ciencias Basicas,
Universidad Catolica del Maule, Talca,
Chile
E-mail: carloshrc1989@gmail.com
molina@imca.edu.pe
Abstract:
In this paper, we consider the diffusive Mackey-Glass model with discrete delay. This equation describes the dynamics of the blood cell production. We investigate the existence of traveling wavefronts solutions connecting the two steady states of the model. We develop an alternative proof of the existence of such solutions and we also demonstrate the existence of traveling wavefronts moving at minimum speed. The proposed approach is based on the use technique of upper-lower solutions. Finally, through an iterative procedure, we show numerical simulations that approximate the traveling wavefronts, thus confirming our theoretical results.
Paper's Title:
Orthogonal Collocation on Finite Elements Using Quintic Hermite Basis
Author(s):
P. Singh, N. Parumasur and C. Bansilal
University of KwaZulu-Natal,
School of Mathematics Statistics and Computer Sciences,
Private Bag X54001,
Durban, 4000,
South Africa.
E-mail: singhprook@gmail.com
parumasurn1@ukzn.ac.za
christelle18@gmail.com
Abstract:
In this paper we consider the orthogonal collocation on finite elements (OCFE) method using quintic Hermite (second degree smooth) basis functions and use it to solve partial differential equations (PDEs). The method is particularly tailored to solve third order BVPS and PDEs and to handle their special solutions such as travelling waves and solitons, which typically is the case in the KdV equation. The use of quintic polynomials and collocation using Gauss points yields a stable high order superconvergent method. OCFE using quintic Hermite basis is optimal since it is computationally more efficient than collocation methods using (first degree smooth) piecewise-polynomials and more accurate than the (third degree smooth) B-splines basis. Various computational simulations are presented to demonstrate the computational efficiency and versatility of the OCFE method.
Paper's Title:
Trace Inequalities for Operators in Hilbert Spaces: a Survey of Recent Results
Author(s):
Sever S. Dragomir1,2
1Mathematics,
School of Engineering
& Science
Victoria University,
PO Box 14428
Melbourne City, MC 8001,
Australia
E-mail: sever.dragomir@vu.edu.au
2DST-NRF Centre of Excellence in the Mathematical and Statistical Sciences,
School of Computer Science & Applied Mathematics,
University of the Witwatersrand,
Private Bag 3, Johannesburg 2050,
South Africa
URL:
https://rgmia.org/dragomir
Abstract:
In this paper we survey some recent trace inequalities for operators in Hilbert spaces that are connected to Schwarz's, Buzano's and Kato's inequalities and the reverses of Schwarz inequality known in the literature as Cassels' inequality and Shisha-Mond's inequality. Applications for some functionals that are naturally associated to some of these inequalities and for functions of operators defined by power series are given. Further, various trace inequalities for convex functions are presented including refinements of Jensen inequality and several reverses of Jensen's inequality. Hermite-Hadamard type inequalities and the trace version of Slater's inequality are given. Some Lipschitz type inequalities are also surveyed. Examples for fundamental functions such as the power, logarithmic, resolvent and exponential functions are provided as well.
Paper's Title:
Preserver of Local Spectrum of Skew-product Operators
Author(s):
Rohollah Parvinianzadeh1,*, Meysam Asadipour2 and Jumakhan Pazhman3
1Department
of Mathematics,
College of Sciences,
University of Yasouj,
Yasouj, 75918-74934,
Iran.
E-mail: r.parvinian@yu.ac.ir
2Department
of Mathematics,
College of Sciences,
University of Yasouj,
Yasouj, 75918-74934,
Iran.
E-mail: Asadipour@yu.ac.ir
3Department
of Mathematics,
Ghor Institute of higher education,
Afghanistan.
E-mail: jumapazhman@gmail.com
Abstract:
Let H and K be infinite-dimensional complex Hilbert spaces, and B(H) (resp. B(K)) be the algebra of all bounded linear operators on H (resp. on K). For an operator T∈ B(H) and a vector h∈ H, let σT(h) denote the local spectrum of T at h. For two nonzero vectors h0∈ H and k0∈ K, we show that if two maps φ1 and φ2 from B(H) into B(K) satisfy
σφ1(T)φ2(S)*(k0)= σTS*(h0})
for all T, S ∈ B(H), and their range containing all operators of rank at most two, then there exist bijective linear maps P : H→ K and Q : K→ H such that φ1(T) = PTQ and φ2(T)* =Q-1T*P-1 for all T ∈ B(H). Also, we obtain some interesting results in this direction.
Paper's Title:
Approximately Dual p-Approximate Schauder Frames
Author(s):
K. Mahesh Krishna and P. Sam Johnson
Stat-Math Unit, Indian Statistical
Institute, Bangalore Centre,
Karnataka 560 059
India.
Department of Mathematical and
Computational Sciences,
National Institute of Technology Karnataka (NITK),
Surathkal, Mangaluru 575 025,
India.
E-mail: kmaheshak@gmail.com
sam@nitk.edu.in
Abstract:
Approximately dual frame in Hilbert spaces was introduced by Christensen and Laugesen to overcome difficulties in constructing dual frames for a given Hilbert space frame. It becomes even more difficult in Banach spaces to construct duals. For this purpose, we introduce approximately dual frames for a class of approximate Schauder frames for Banach spaces and develop basic theory. Approximate dual for this subclass is completely characterized and its perturbation is also studied.
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