ORIGINAL_ARTICLE
Arens-irregularity of tensor product of Banach algebras
We introduce Banach algebras arising from tensor norms. By these Banach algebras we make Arensregular Banach algebras such that tensor product becomes irregular, where is tensor norm. Weillustrate injective tensor product, does not preserve bounded approximate identity and it is notalgebra norm.
https://ijnaa.semnan.ac.ir/article_110_b4abcb01c04089ee8011111f76b3eb00.pdf
2014-01-01
1
8
10.22075/ijnaa.2014.110
T.
Yazdanpanah
1
aDepartment of Mathematics, Persian Gulf University, Boushehr, 75168, Iran.
LEAD_AUTHOR
R.
Gharibi
2
aDepartment of Mathematics, Persian Gulf University, Boushehr, 75168, Iran.
AUTHOR
ORIGINAL_ARTICLE
Certain subalgebras of Lipschitz algebras of infinitely differentiable functions and their maximal ideal spaces
We study an interesting class of Banach function algebras of innitely dierentiable functions onperfect, compact plane sets. These algebras were introduced by Honary and Mahyar in 1999, calledLipschitz algebras of innitely dierentiable functions and denoted by Lip(X;M; ), where X is aperfect, compact plane set, M = fMng1n=0 is a sequence of positive numbers such that M0 = 1 and(m+n)!Mm+n ( m!Mm)( n!Mn) for m; n 2 N [ f0g and 2 (0; 1]. Let d = lim sup( n!Mn)1n and Xd = fz 2 C :dist(z;X) dg. Let LipP;d(X;M; )[LipR;d(X;M; )] be the subalgebra of all f 2 Lip(X;M; )that can be approximated by the restriction to Xd of polynomials [rational functions with poles oXd]. We show that the maximal ideal space of LipP;d(X;M; ) is cXd, the polynomially convex hullof Xd, and the maximal ideal space of LipR;d(X;M; ) is Xd, for certain compact plane sets.. Usingsome formulae from combinatorial analysis, we nd the maximal ideal space of certain subalgebrasof Lipschitz algebras of innitely dierentiable functions.
https://ijnaa.semnan.ac.ir/article_111_3aee2736a32d307e34b4d8bc34fafb5a.pdf
2014-01-01
9
22
10.22075/ijnaa.2014.111
D.
Alimohammadi
1
Department of Mathematics, Faculty of Science, Arak University, P. O. Box: 38156-8-8349, Arak, Iran.
LEAD_AUTHOR
F.
Nezamabadi
2
Department of Mathematics, Faculty of Science, Arak University, P. O. Box: 38156-8-8349, Arak, Iran.
AUTHOR
ORIGINAL_ARTICLE
Ternary (\sigma,\tau,\xi)-derivations on Banach ternary algebras
Let A be a Banach ternary algebra over a scalar eld R or C and X be a Banach ternary A-module.Let ; and be linear mappings on A, a linear mapping D : (A; [ ]A) ! (X; [ ]X) is called a ternary(; ; )-derivation, ifD([xyz]A) = [D(x) (y)(z)]X + [(x)D(y)(z)]X + [(x) (y)D(z)]Xfor all x; y; z 2 A.In this paper, we investigate ternary (; ; )-derivation on Banach ternary algebras, associatedwith the following functional equationf(x + y + z4) + f(3x y 4z4) + f(4x + 3z4) = 2f(x) :Moreover, we prove the generalized Ulam{Hyers stability of ternary (; ; )-derivations on Banachternary algebras.
https://ijnaa.semnan.ac.ir/article_112_ecfffaca50a5c1a9f09e21fc58595127.pdf
2014-01-01
23
35
10.22075/ijnaa.2014.112
M.
Eshaghi Gordji
1
Department of Mathematics, Semnan University, P. O. Box 35195-363, Semnan, Iran.
LEAD_AUTHOR
F.
Farrokhzad
2
Department of Mathematics, Shahid Beheshti University, Tehran, Iran.
AUTHOR
S.A.R.
Hosseinioun
3
Department of Mathematical Sciences, University of Arkansas, Fayetteville, Arkansas 72701, USA.
AUTHOR
ORIGINAL_ARTICLE
Contractive maps in Mustafa-Sims metric spaces
The xed point result in Mustafa-Sims metrical structures obtained by Karapinar and Agarwal[Fixed Point Th. Appl., 2013, 2013:154] is deductible from a corresponding one stated in terms ofanticipative contractions over the associated (standard) metric space.
https://ijnaa.semnan.ac.ir/article_113_0b35677d1efa6cc2becda06023b6e04d.pdf
2014-01-01
36
53
10.22075/ijnaa.2014.113
M.
Turinici
1
"A. Myller" Mathematical Seminar, "A. I. Cuza" University, 700506 Iasi, Romania.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Tripled partially ordered sets
In this paper, we introduce tripled partially ordered sets and monotone functions on tripled partiallyordered sets. Some basic properties on these new dened sets are studied and some examples forclarifying are given.
https://ijnaa.semnan.ac.ir/article_114_42e7a53b23613e649516a8991bc7f54e.pdf
2014-01-01
54
63
10.22075/ijnaa.2014.114
M.
Eshaghi
1
Department of Mathematics, Semnan University, P. O. Box 35195-363, Semnan, Iran
LEAD_AUTHOR
A.
Jabbari
2
Department of Mathematics, Ardabil Branch, Islamic Azad University, Ardabil, Iran
AUTHOR
S.
Mohseni
3
Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran.
AUTHOR
ORIGINAL_ARTICLE
A fixed point result for a new class of set-valued contractions
In this paper, we introduce a new class of set-valued contractions and obtain a xed point theoremfor such mappings in complete metric spaces. Our main result generalizes and improves many well-known xed point theorems in the literature.
https://ijnaa.semnan.ac.ir/article_115_04704abdd8d440603dc84fa5e05cfff9.pdf
2014-01-01
64
70
10.22075/ijnaa.2014.115
A.
Sadeghi Hafjejani
1
Department of Mathematics, University of Shahrekord, Shahrekord, 88186-34141, Iran.
AUTHOR
A.
Amini Harandi
2
Department of Mathematics, University of Shahrekord, Shahrekord, 88186-34141, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
On a more accurate multiple Hilbert-type inequality
By using Euler-Maclaurin's summation formula and the way of real analysis, a more accurate multipleHilbert-type inequality and the equivalent form are given. We also prove that the same constantfactor in the equivalent inequalities is the best possible.
https://ijnaa.semnan.ac.ir/article_116_ea3df0090bfbe87b3cfe918003fb4766.pdf
2014-01-01
71
79
10.22075/ijnaa.2014.116
Q.
Huang
1
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China.
AUTHOR
B.
Yang
2
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China.
LEAD_AUTHOR
ORIGINAL_ARTICLE
A multidimensional discrete Hilbert-type inequality
In this paper, by using the way of weight coecients and technique of real analysis, a multidimensionaldiscrete Hilbert-type inequality with a best possible constant factor is given. The equivalentform, the operator expression with the norm are considered.
https://ijnaa.semnan.ac.ir/article_117_ad1285ddb601787b355b2ddbba08a66f.pdf
2014-01-01
80
88
10.22075/ijnaa.2014.117
B.
Yang
1
Department of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China.
LEAD_AUTHOR
ORIGINAL_ARTICLE
A companion of Ostrowski's inequality for functions of bounded variation and applications
A companion of Ostrowski's inequality for functions of bounded variation and applications are given.
https://ijnaa.semnan.ac.ir/article_118_8b6d57c3efcc79541d89acc0de017063.pdf
2014-01-01
89
97
10.22075/ijnaa.2014.118
S.S.
Dragomir
1
School of Computational & Applied Mathematics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Some new extensions of Hardy`s inequality
In this study, by a non-negative homogeneous kernel k we prove some extensions of Hardy's inequalityin two and three dimensions
https://ijnaa.semnan.ac.ir/article_119_3350455c94f51970ab2121f655161633.pdf
2014-01-01
98
109
10.22075/ijnaa.2014.119
A.R.
Moazzen
1
Department of Mathematics, Velayat University, Iranshahr, Iran.
LEAD_AUTHOR
R.
Lashkaripour
2
Department of Mathematics, University of Sistan and Baluchestan, Zahedan, Iran.
AUTHOR