2014
5
1
1
109
1

Arensirregularity of tensor product of Banach algebras
https://ijnaa.semnan.ac.ir/article_110.html
10.22075/ijnaa.2014.110
1
We introduce Banach algebras arising from tensor norms. By these Banach algebras, we make Arens regular Banach algebras such that $alpha$ the tensor product becomes irregular, where $alpha$ is tensor norm. We illustrate injective tensor product, does not preserve bounded approximate identity and it is not algebra norm.
0

1
8


T.
Yazdanpanah
Department of Mathematics, Persian Gulf University, Boushehr, 75168, Iran
Iran


R.
Gharibi
Department of Mathematics, Persian Gulf University, Boushehr, 75168, Iran
Iran
Arens products
Arens regularity
compact operators
approximable operators
nuclear operators
tensor norm
approximate identity
approximation property
1

Certain subalgebras of Lipschitz algebras of infinitely differentiable functions and their maximal ideal spaces
https://ijnaa.semnan.ac.ir/article_111.html
10.22075/ijnaa.2014.111
1
We study an interesting class of Banach function algebras of infinitely differentiable functions on perfect, compact plane sets. These algebras were introduced by Honary and Mahyar in 1999, called Lipschitz algebras of infinitely differentiable functions and denoted by $Lip(X,M, alpha)$, where $X$ is a perfect, compact plane set, $M ={M_n}_{n=0}^infty$ is a sequence of positive numbers such that $M_0 = 1$ and $frac{(m+n)!}{M_{m+n}}leq(frac{m!}{M_m})(frac{n!}{M_n})$, for $m, n inmathbb{N} cup{0}$ and $alphain (0, 1]$. Let $d =lim sup(frac{n!}{M_n})^{frac{1}{n}}$ and $X_d ={z inmathbb{C} : dist(z,X)leq d}$. Let $Lip_{P,d}(X,M, alpha)$ [$Lip_{R,d}(X,M alpha)$] be the subalgebra of all $f in Lip(X,M,alpha)$ that can be approximated by the restriction to $X_d$ of polynomials [rational functions with poles $X_d$]. We show that the maximal ideal space of $Lip_{P,d}(X,M, alpha)$ is $widehat{X_d}$, the polynomially convex hull of $X_d$, and the maximal ideal space of $Lip_{R,d}(X,M alpha)$ is $X_d$, for certain compact plane sets. Using some formulae from combinatorial analysis, we find the maximal ideal space of certain subalgebras of Lipschitz algebras of infinitely differentiable functions.
0

9
22


D.
Alimohammadi
Department of Mathematics, Faculty of Science, Arak University, P. O. Box: 3815688349, Arak, Iran.
Iran


F.
Nezamabadi
Department of Mathematics, Faculty of Science, Arak University, P. O. Box: 3815688349, Arak, Iran.
Iran
Infinitely differentiable functions
Function algebra
Lipschitz algebra
Maximal ideal space
Starshaped set
Uniformly regular
1

Ternary $(sigma,tau,xi)$derivations on Banach ternary algebras
https://ijnaa.semnan.ac.ir/article_112.html
10.22075/ijnaa.2014.112
1
Let $A$ be a Banach ternary algebra over a scalar field $mathbb{R}$ or $mathbb{C}$ and $X$ be a Banach ternary $A$module. Let $sigma, tau$ and $xi$ be linear mappings on $A$, a linear mapping $D : (A,[ ]_A) to (X, [ ]_X)$ is called a ternary $(sigma,tau,xi)$derivation, if$$D([xyz]_A) = [D(x)tau(y)xi(z)]_X + [sigma(x)D(y)xi(z)]_X + [sigma(x)tau(y)D(z)]_X$$for all $x,y, z in A$. In this paper, we investigate ternary $(sigma,tau,xi)$derivation on Banach ternary algebras, associated with the following functional equation$$f(frac{x + y + z}{4}) + f(frac{3x  y  4z}{4}) + f(frac{4x + 3z}{4}) = 2f(x).$$Moreover, we prove the generalized UlamHyers stability of ternary $(sigma,tau,xi)$derivations on Banach ternary algebras.
0

23
35


M.
Eshaghi Gordji
Department of Mathematics, Semnan University, P. O. Box 35195363, Semnan, Iran.
Iran


F.
Farrokhzad
Department of Mathematics, Shahid Beheshti University, Tehran, Iran.
Iran


S.A.R.
Hosseinioun
Department of Mathematical Sciences, University of Arkansas, Fayetteville, Arkansas 72701, USA
United States
Banach ternary algebra
Banach ternary $A$module
Ternary $(sigma,tau,xi)$derivation
1

Contractive maps in MustafaSims metric spaces
https://ijnaa.semnan.ac.ir/article_113.html
10.22075/ijnaa.2014.113
1
The fixed point results in MustafaSims metrical structures obtained by Karapinar and Agarwal [Fixed Point Th. Appl., 2013, 2013:154] is deductible from a corresponding one stated in terms of anticipative contractions over the associated (standard) metric space.
0

36
53


M.
Turinici
"A. Myller" Mathematical Seminar, "A. I. Cuza" University, 700506 Iasi, Romania
Romania
metric space
globally strong Picard operator
functional anticipative contraction
Dhage and MustafaSims metric
convergent and Cauchy sequence
strong triangle inequality
1

Tripled partially ordered sets
https://ijnaa.semnan.ac.ir/article_114.html
10.22075/ijnaa.2014.114
1
In this paper, we introduce tripled partially ordered sets and monotone functions on tripled partially ordered sets. Some basic properties on these new defined sets are studied and some examples for clarifying are given.
0

54
63


M.
Eshaghi
Department of Mathematics, Semnan University, P. O. Box 35195363, Semnan, Iran
Iran


A.
Jabbari
Department of Mathematics, Ardabil Branch, Islamic Azad University, Ardabil, Iran
Iran


S.
Mohseni
Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran.
Iran
partially ordered set
upper bound
Lower bound
monotone function
1

A fixed point result for a new class of setvalued contractions
https://ijnaa.semnan.ac.ir/article_115.html
10.22075/ijnaa.2014.115
1
In this paper, we introduce a new class of setvalued contractions and obtain a fixed point theorem for such mappings in complete metric spaces. Our main result generalizes and improves many wellknown fixed point theorems in the literature.
0

64
70


A.
Sadeghi Hafjejani
Department of Mathematics, University of Shahrekord,
Shahrekord, 8818634141, Iran.
Iran


A.
Amini Harandi
Department of Mathematics, University of Shahrekord,
Shahrekord, 8818634141, Iran.
Iran
Fixed point
Setvalued contraction
1

On a more accurate multiple Hilberttype inequality
https://ijnaa.semnan.ac.ir/article_116.html
10.22075/ijnaa.2014.116
1
By using EulerMaclaurin's summation formula and the way of real analysis, a more accurate multiple Hilberttype inequality and the equivalent form are given. We also prove that the same constant factor in the equivalent inequalities is the best possible.
0

71
79


Q.
Huang
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China
China


B.
Yang
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China
China
Multiple HilbertType Inequality
weight coefficient
EulerMaclaurin’s Summation Formula
1

A multidimensional discrete Hilberttype inequality
https://ijnaa.semnan.ac.ir/article_117.html
10.22075/ijnaa.2014.117
1
In this paper, by using the way of weight coefficients and technique of real analysis, a multidimensional discrete Hilberttype inequality with the best possible constant factor is given. The equivalent form, the operator expression with the norm are considered.
0

80
88


B.
Yang
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China.
China
Hilbert’s Inequality
weight coefficient
equivalent form
operator
norm
1

A companion of Ostrowski's inequality for functions of bounded variation and applications
https://ijnaa.semnan.ac.ir/article_118.html
10.22075/ijnaa.2014.118
1
A companion of Ostrowski's inequality for functions of bounded variation and applications are given.
0

89
97


S.S.
Dragomir
School of Computational & Applied Mathematics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050,
South Africa.
South Africa
Ostrowski’s Inequality
Trapezoid Rule
Midpoint Rule
1

Some new extensions of Hardy`s inequality
https://ijnaa.semnan.ac.ir/article_119.html
10.22075/ijnaa.2014.119
1
In this study, by a nonnegative homogeneous kernel k we prove some extensions of Hardy's inequality in two and three dimensions
0

98
109


A.R.
Moazzen
Department of Mathematics, Velayat University, Iranshahr, Iran.
Iran


R.
Lashkaripour
Department of Mathematics, University of Sistan and Baluchestan, Zahedan, Iran.
Iran
Hardy‘s inequality
Integral inequality
RiemannLioville integral