eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
1
26
320
Beyond First Order Logic: From number of structures to structure of
numbers: Part I
J. Baldwin
jbaldwin@uic.edu
1
T. Hyttinen
tapani.hyttinen@helsinki.fi
2
M. Kesala
meeri.kesala@helsinki.fi
3
University of Illinois at Chicago
Department of Mathematics and Statistics University of Helsinki
Department of Mathematics and Statistics University of Helsinki
We study the history and recent developments in nonelementary<br />model theory focusing on the framework of abstract<br />elementary classes. We discuss the role of syntax and semantics<br />and the motivation to generalize first order model theory to nonelementary<br />frameworks and illuminate the study with concrete examples<br />of classes of models. <br /><br />This first part introduces the main conceps and philosophies and<br />discusses two research questions, namely categoricity transfer and<br />the stability classification.
http://bims.iranjournals.ir/article_320_2a3d9a459a6dc5deea92274b7c87226a.pdf
Mathematical logic
model theory
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
27
48
409
Beyond first order logic: From number of structures to structure of numbers: Part II
J. Baldwin
jbaldwin@uic.edu
1
T. Hyttinen
tapani.hyttinen@helsinki.fi
2
M. Kesala
meeri.kesala@helsinki.fi
3
University of Illinois at Chicago, USA
University of Helsinki, Finland
University of Helsinki, Finland
We study the history and recent developments in nonelementary<br />model theory focusing on the framework of abstract<br />elementary classes. We discuss the role of syntax and semantics<br />and the motivation to generalize first order model theory to nonelementary<br />frameworks and illuminate the study with concrete examples<br />of classes of models. <br /><br />This second part continues to study the question of catecoricity<br />transfer and counting the number of structures of certain cardinality.<br />We discuss more thoroughly the role of countable models,<br />search for a non-elementary counterpart for the concept of completeness<br />and present two examples: one example answers a question<br />asked by David Kueker and the other investigates models of<br />Peano Arithmetic and the relation of an elementary end-extension<br />in terms of an abstract elementary class.
http://bims.iranjournals.ir/article_409_972adc8069030d13b7a9ea9a157ed273.pdf
Mathematical logic
model theory
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
49
64
233
Generalized Rings of Measurable and Continuous Functions
A. Amini
aamini@shirazu.ac.ir
1
B. Amini
bamini@shirazu.ac.ir
2
E. Momtahan
momtahan_e@hotmail.com
3
M. H. Shirdareh Haghigi
shirdareh@susc.ac.ir
4
Shiraz University
Shiraz University
Yasouj University
Shiraz University
This paper is an attempt to generalize, simultaneously, the ring <br />of real-valued continuous functions and the ring of real-valued <br />measurable functions.
http://bims.iranjournals.ir/article_233_c2ebf0d719858815bd653683ce485ae3.pdf
rings of continuous functions
rings of measurable
functions
regular rings
$aleph_0$-self-injective rings
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
65
85
305
Grouplikes
M. H. Hooshmand
hadi.hooshmand@gmail.com
1
Islamic Azad University - Shiraz Branch
In this paper we introduce and study an algebraic structure, namely <br />Grouplike. A grouplike is something between semigroup and group and <br />its axioms are generalizations of the four group axioms. <br />Every grouplike is a semigroup containing the minimum ideal that is also a maximal subgroup (but the converse is not valid). <br />The first idea of grouplikes comes from b-parts and $b$-addition <br />of real numbers introduced by the author. Now, the researches have enabled me to <br />introduce Grouplikes and prove some of their main theorems <br />and construct a vast class of them, here. We prove <br />a fundamental structure theorem for a big class of grouplikes, namely <br />Class United Grouplikes. Moreover, we obtain some other results for <br />binary systems, semigroups and groups in general and exhibit several <br />their important subsets with related diagrams. Finally. we show some of future directions <br />for the researches in grouplikes and semigroup theory.
http://bims.iranjournals.ir/article_305_daa595cb8449dd1f6b4a0cb354aefa32.pdf
Grouplike
class united grouplike
identity-like
grouplike homomorphism
real b-grouplike
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
87
95
335
Brandt extensions and primitive topologically periodic inverse topological semigroups
J. Jamalzadeh
jamalzadeh1980@yahoo.com
1
Gh. Rezaei
grezaei@hamoon.usb.ac.ir
2
I am phd student in sistan and bluchestan university
University of Sistan and Bluchestan, Iran
In this paper we find sufficient conditions on primitive inverse <br />topological semigroup S under which: the inversion inv : (H(S)) (H(S)) <br />is continuous; we show that every topologically periodic countable compact <br />primitive inverse topological semigroups with closed H-classes is topologically <br />isomorphic to an orthogonal sum <br />P <br />i2= Bi (Gi) of topological Brandt extensions Bi (Gi) of countably compact topological groups Gi in the class <br />of topological inverse semigroups for some finite cardinals.
http://bims.iranjournals.ir/article_335_d5c026c53354c9bcbfe4d7fe7e5c649e.pdf
inverse topological semigroup
Topological inverse semigroup
0-
simple group
completely 0-simple semigroup
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
97
106
239
On the relations between the point spectrum of A and invertibility of I + f(A)B
H. Larki
h.larki@gmail.com
1
A. Riazi
riazi@aut.ac.ir
2
Islamic Azad University, Parand Branch
Amirkabir University of Technology
Let A be a bounded linear operator on a Banach space X. We <br />investigate the conditions of existing rank-one operator B such that I+f(A)B is invertible for every analytic function <br />f on sigma(A). Also we compare the invariant subspaces of f(A)B and B. This work is motivated by an <br />operator method on the Banach space ell^2 for solving some PDEs which is extended to general operator space under some <br />conditions in this paper.
http://bims.iranjournals.ir/article_239_aa94bb32deb5aba560c323c06fd34102.pdf
point spectrum
rank-one operator
invariant subspaces
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
107
124
222
On a subclass of multivalent analytic functions associated with an extended fractional differintegral operator
J.-L. Liu
jlliu@yzu.edu.cn
1
Department of Mathematics, Yangzhou University
Making use of an extended fractional differintegral operator ( introduced recently by Patel and Mishra), we introduce a new subclass of multivalent analytic functions and investigate certain interesting properties of this subclass.
http://bims.iranjournals.ir/article_222_b55977251c75b2af4170f508df58c24c.pdf
analytic function
Multivalent function
fractional differintegral operator
convex univalent function
Subordination
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
125
149
410
The two parameter quantum groups
$U_{r,s}(mathfrak{g})$ associated to generalized Kac-Moody algebra
and their equitable presentation
Q. Sun
qxsun@126.com
1
H. Li
honglli@126.com
2
Zhejiang University of Science and Technology, China
Zhejiang International Studies University, China
We construct a family of two parameter quantum grou-\ps
$U_{r,s}(mathfrak{g})$ associated with a generalized Kac-Moody
algebra corresponding to symmetrizable admissible Borcherds Cartan
matrix. We also construct the $textbf{A}$-form $U_{textbf{A}}$ and
the classical limit of $U_{r,s}(mathfrak{g})$. Furthermore, we
display the equitable presentation for a subalgebra
$U_{r,s}^{b-}(mathfrak{g} )$ of $U_{r,s}(mathfrak{g})$ and show
that this presentation has the attractive feature that all of its
generators act semisimply on finite dimensional irreducible
$U_{r,s}(mathfrak{g})$-modules associated with the Kac-Moody algebra.
http://bims.iranjournals.ir/article_410_9c4af9233d4d3e488f54d9d44c7ea5bd.pdf
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
151
164
342
Essential norm of generalized composition operators from
weighted Dirichlet or Bloch type spaces to Q_K type spaces
Sh. Rezaei
sh.rezaei@srbiau.ac.ir
1
H. Mahyar
mahyar@khu.ac.ir
2
Islamic Azad University, Iran
Tarbiat Moallem University, Iran
In this paper we obtain lower and upper estimates for the <br />essential norms of generalized composition operators from weighted <br />Dirichlet spaces or Bloch type spaces to $Q_K$ type <br />spaces.
http://bims.iranjournals.ir/article_342_7297405479aa435b72d575295ddb0380.pdf
Bloch type space
weighted Dirichlet space
$Q_K$ type space
generalized composition operator
essential norm
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
165
173
343
Existence and uniqueness of solutions for a periodic
boundary value problem
A. Amini Harandi
aminih_a@yahoo.com
1
University of Shahrekord, Iran
In this paper, using the fixed point theory in cone metric spaces, we prove the existence of a unique solution to a first-order ordinary differential equation with periodic boundary conditions in Banach spaces admitting the existence of a lower solution.
http://bims.iranjournals.ir/article_343_4afacfa2a4973fe9304d888b866fd3ae.pdf
fixed point
Periodic boundary value problem
Banach lattice
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
175
185
339
The Quasi-morphic Property of Group
Q. Wang
wangqichuan1026@163.com.cn
1
K. Long
lkkkkkkkk@hotmail.com.cn
2
L. Feng
fenglg2002@sina.com.cn
3
Department of Mathematics and Systems Science, National University of Defense Technology, P.R.China 410073,Changsha, China.
Department of Mathematics and Systems Science, National University of Defense Technology ,P.R.China 410073, Changsha, China.
Department of Mathematics and Systems Science, National University of Defense Technology, P.R.China 410073, Changsha, China.
A group is called morphic if for each normal endomorphism α in end(G),there exists β such that ker(α)= Gβ and Gα= ker(β). In this paper, we consider the case that there exist normal endomorphisms β and γ such that ker(α)= Gβ and Gα = ker(γ). We call G quasi-morphic, if this happens for any normal endomorphism α in end(G). We get the following results: G is quasi-morphic if and only if, for any normal subgroup K and N such that G/K≌N, there exist normal subgroup T and H such that G/T≌K and G/N≌H. Further, we investigate the quasi-morphic property of finitely generated abelian group and get that a finitely generated abelian group is quasi-morphic if and only if it is finite.
http://bims.iranjournals.ir/article_339_e1fa74b090c7cf943c21d3c24a31908a.pdf
quasi-morphic group
finitely generated abelian group
normal endomorphism
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
187
192
341
Maximal subsets of pairwise non-commuting elements of some finite p-groups
A. Azad
a.azad1347@gmail.com
1
S. Fouladi
s_fouladi@khu.ac.ir
2
R. Orfi
r-orfi@araku.ac.ir
3
Arak University, Iran
Kharazmi University, Iran
Arak University, Iran
Let G be a group. A subset X of G is a set of pairwise noncommuting <br />elements if xy ̸= yx for any two distinct elements x and y in X. <br />If |X| ≥ |Y | for any other set of pairwise non-commuting elements Y in G, <br />then X is said to be a maximal subset of pairwise non-commuting elements. <br />In this paper we determine the cardinality of a maximal subset of pairwise <br />non-commuting elements in any non-abelian p-groups with central quotient <br />of order less than or equal to p3 for any prime number p. As an immediate <br />consequence we give this cardinality for any non-abelian group of order p4.
http://bims.iranjournals.ir/article_341_ed95cc075963c4991eb4ff3398515d7c.pdf
pairwise non-commuting elements
Finite p-group
AC-group
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
193
203
345
$varepsilon$-Simultaneous approximations
of downward sets
H. Alizadeh
halizadeh@marandiau.ac.ir
1
Sh. Rezapour
sh.rezapour@azaruniv.edu
2
S. Vaezpour
vaez@aut.ac.ir
3
Islamic Aazad University, Marand, Iran
Azarbaidjan University of Tarbiat Moallem, Iran
Amirkabir University of Technology, Iran
In this paper, we prove some results on characterization of $varepsilon$-simultaneous approximations of downward sets in vector lattice Banach spaces. Also, we give some results about simultaneous approximations of normal sets.
http://bims.iranjournals.ir/article_345_3d1cd47063aa5b80dbcd37a8684f8675.pdf
$varepsilon$-simultaneous approximation
Downward set
Lattice Banach space
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-03-01
39
1
205
223
338
Spacelike hypersurfaces in Riemannian or Lorentzian space forms satisfying L_k(x)=Ax+b
F. Pashaie
f_pashaie@yahoo.com
1
S.M.B. Kashani
kashanism@yahoo.com
2
Tarbiat Modares University, Iran
Tarbiat Modares University
We study connected <br />orientable spacelike hypersurfaces <br />$x:M^{n}rightarrowM_q^{n+1}(c)$, isometrically immersed into the <br />Riemannian or Lorentzian space form of curvature $c=-1,0,1$, and <br />index $q=0,1$, satisfying the condition $~L_kx=Ax+b$,~ <br /> where $L_k$ is the $textit{linearized operator}$ of <br />the $(k+1)$-th mean curvature $H_{k+1}$ of the hypersurface for a <br />fixed integer $0leq k<n$, $A$ is a constant matrix and $b$ is a <br />constant vector. <br /> <br />We show that the only hypersurfaces satisfying that condition are <br />hypersurfaces with zero $H_{k+1}$ and constant $H_k$ ( when $cneq <br />0$ ), open pieces of totally umbilic hypersurfaces and open pieces <br />of the standard Riemannian product of two totally umbilic <br />hypersurfaces.
http://bims.iranjournals.ir/article_338_564a4b1f52aa0e44c763a92cfc8189b5.pdf
Linearized operator $L_k$
Higher order mean
curvatures
Lorentzian space forms