ORIGINAL_ARTICLE
Toeplitzness of weighted composition operators
For a bounded analytic map ψ on the unit disk D and analytic self-map φ of D, a weighted composition operator Cψ,φ on the Hardy space H2=H2(D) is defined by Cψ,φf= ψ·f°φ. In this paper, we study the asymptotically Toeplitzness of weighted composition operators and their adjoints in different topology on B(H2).
http://www.macajournal.com/article_679850_9db7eedf0ba45d1c154ac176cdcda0b7.pdf
2020-10-07
1
8
10.30495/maca.2020.679850
Hardy space
asymptotically Toeplitz operator
weighted composition operator
Massoud
Salehi Sarvestani
m.salehisarvestani@gmail.com
1
Department of mathematics, Savadkoh Branch, Islamic Azad university, Savadkoh, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
A simple method to solve nonlinear Volterra-Fredholm integro-differential equations
In this paper, a new simple direct method to solve nonlinear Fredholm-Volterra integral equations is presented. By using Block-pulse (BP) functions, their operational matrices and Taylor expansion a nonlinear Fredholm-Volterra integral equation converts to a nonlinear system. Some numerical examples illustrate accuracy and reliability of our solutions. Moreover, the effect of noise shows our method is stable.
http://www.macajournal.com/article_679851_ad46a7983a43e1a3b40524926c85c045.pdf
2020-10-15
9
16
10.30495/maca.2020.679851
Nonlinear Volterra-Fredholm integro-differential equation
Block-pulse functions
Taylor expansion
Operational matrices
Mohsen
Mohamadi
m.mohamadi2000@gmail.com
1
Department of mathematics, Ayatollah Amoli Branch, Islamic Azad University, Amol,Iran
LEAD_AUTHOR
Amir
Shahmari
ashahmari@gmail.com
2
Department of mathematics, Ayatollah Amoli Branch, Islamic Azad University, Amol,Iran
AUTHOR
ORIGINAL_ARTICLE
The generalized Hyers–Ulam stability of derivations in non-Archimedean Banach algebras
In this paper, the generalized Hyers-Ulam stability of the functional inequality||f(a)+f(b)+cf(d)+f(c)d||≤||kf((a+b+cd)/k)||, |k|<|2|,in non-Archimedean Banach algebras is established.
http://www.macajournal.com/article_679852_de31b1247703ab54339d5627fa628ab8.pdf
2020-11-29
17
22
10.30495/maca.2020.679852
Banach algebra
derivation
Generalized Hyers-Ulam stability
Non-Archimedean Banach algebra
Abolfazl
Niazi Motlagh
a.niazi@ub.ac.ir
1
Department of Mathematics, Faculty of Basic Sciences, University of Bojnord, Bojnord, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Locally finite inverse semigroups
In this article, we study locally finite inverse semigroup S and characterize the structure of idempotents of S which are either a well-ordered countable chain or union of disjoint well-ordered countable chains. We also prove that whenS is a locally finite Clifford semigroup, S is amenable if and only if minimal ideal of S is amenable.
http://www.macajournal.com/article_679854_5ac3e5597ff0061ee9bb3736fc030560.pdf
2020-11-16
23
27
10.30495/maca.2020.679854
amenability
inverse semigroup
Clifford semigroup
locally finite semigroup
Somaye
Grailoo Tanha
grailotanha@gmail.com
1
Esfarayen University of Technology, Esfarayen, North Khorasan, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Certain dense subalgebras of continuous vector-valued operator algebras
Let X be a compact metric space with at least two elements, B be a unital commutative Banach algebra over the scalar field F=R or C, and α in R with 0<α≤1. Suppose that C(X,B) be the continuous, A(X,B) be the analytic, and Lipα(X,B) be the α-Lipschitz B-valued operator algebras on X. In this paper, we prove that the algebras Lip α(X,B) and A(X,B) are dense in C(X,B) under sup-norm. Also, we study the relationship between elements of the algebras Lip α(X,B) and A(X,B).
http://www.macajournal.com/article_679855_52bad764f50e390f61cd63b662ef82a5.pdf
2020-12-16
28
34
10.30495/maca.2020.679855
Dense
Banach algebra
Lipschitz algebra
Vector-valued operator
Abbasali
Shokri
a-shokri@iau-ahar.ac.ir
1
Department of Mathematics, Ahar Branch, Islamic Azad University, Ahar, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
A new notion of affine sets
In this paper, we investigate the behaviour of e-convex sets and e-affine sets. Moreover, some notions like S(e,a,ρ,α) and e-affine cones are introduced and discussed. We complete with a role of above sets in linear idempotent maps.
http://www.macajournal.com/article_679857_68002c613d63b1e175cf1f4662ed0e11.pdf
2020-12-25
35
42
10.30495/maca.2020.679857
Affine sets
e-convex sets
e-cone
e-affine set
Paulraj
Gnanachandra
pgchandra07@gmail.com
1
Centre for Research and Post Graduate Studies in Mathematics, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi-626124, Tamil Nadu, India
LEAD_AUTHOR
Mohan
Arunkumar
annarun2002@gmail.com
2
Department of Mathematics, Government Arts College, Tiruvannamalai-606 603, Tamil Nadu, India.
AUTHOR