Beyond First Order Logic: From number of structures to structure of
numbers: Part I
J.
Baldwin
University of Illinois at Chicago
author
T.
Hyttinen
Department of Mathematics and Statistics
University of Helsinki
author
M.
Kesala
Department of Mathematics and Statistics
University of Helsinki
author
text
article
2013
eng
We study the history and recent developments in nonelementarymodel theory focusing on the framework of abstractelementary classes. We discuss the role of syntax and semanticsand the motivation to generalize first order model theory to nonelementaryframeworks and illuminate the study with concrete examplesof classes of models. This first part introduces the main conceps and philosophies anddiscusses two research questions, namely categoricity transfer andthe stability classification.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
1
26
http://bims.iranjournals.ir/article_320_2a3d9a459a6dc5deea92274b7c87226a.pdf
Beyond first order logic: From number of structures to structure of numbers: Part II
J.
Baldwin
University of Illinois
at Chicago, USA
author
T.
Hyttinen
University of Helsinki, Finland
author
M.
Kesala
University of Helsinki, Finland
author
text
article
2013
eng
We study the history and recent developments in nonelementarymodel theory focusing on the framework of abstractelementary classes. We discuss the role of syntax and semanticsand the motivation to generalize first order model theory to nonelementaryframeworks and illuminate the study with concrete examplesof classes of models. This second part continues to study the question of catecoricitytransfer and counting the number of structures of certain cardinality.We discuss more thoroughly the role of countable models,search for a non-elementary counterpart for the concept of completenessand present two examples: one example answers a questionasked by David Kueker and the other investigates models ofPeano Arithmetic and the relation of an elementary end-extensionin terms of an abstract elementary class.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
27
48
http://bims.iranjournals.ir/article_409_972adc8069030d13b7a9ea9a157ed273.pdf
Generalized Rings of Measurable and Continuous Functions
A.
Amini
Shiraz University
author
B.
Amini
Shiraz University
author
E.
Momtahan
Yasouj University
author
M. H.
Shirdareh Haghigi
Shiraz University
author
text
article
2013
eng
This paper is an attempt to generalize, simultaneously, the ring of real-valued continuous functions and the ring of real-valued measurable functions.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
49
64
http://bims.iranjournals.ir/article_233_c2ebf0d719858815bd653683ce485ae3.pdf
Grouplikes
M. H.
Hooshmand
Islamic Azad University - Shiraz Branch
author
text
article
2013
eng
In this paper we introduce and study an algebraic structure, namely Grouplike. A grouplike is something between semigroup and group and its axioms are generalizations of the four group axioms. Every grouplike is a semigroup containing the minimum ideal that is also a maximal subgroup (but the converse is not valid). The first idea of grouplikes comes from b-parts and $b$-addition of real numbers introduced by the author. Now, the researches have enabled me to introduce Grouplikes and prove some of their main theorems and construct a vast class of them, here. We prove a fundamental structure theorem for a big class of grouplikes, namely Class United Grouplikes. Moreover, we obtain some other results for binary systems, semigroups and groups in general and exhibit several their important subsets with related diagrams. Finally. we show some of future directions for the researches in grouplikes and semigroup theory.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
65
85
http://bims.iranjournals.ir/article_305_daa595cb8449dd1f6b4a0cb354aefa32.pdf
Brandt extensions and primitive topologically periodic inverse topological semigroups
J.
Jamalzadeh
I am phd student in sistan and bluchestan university
author
Gh.
Rezaei
University of Sistan and Bluchestan, Iran
author
text
article
2013
eng
In this paper we find sufficient conditions on primitive inverse topological semigroup S under which: the inversion inv : (H(S)) (H(S)) is continuous; we show that every topologically periodic countable compact primitive inverse topological semigroups with closed H-classes is topologically isomorphic to an orthogonal sum P i2= Bi (Gi) of topological Brandt extensions Bi (Gi) of countably compact topological groups Gi in the class of topological inverse semigroups for some finite cardinals.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
87
95
http://bims.iranjournals.ir/article_335_d5c026c53354c9bcbfe4d7fe7e5c649e.pdf
On the relations between the point spectrum of A and invertibility of I + f(A)B
H.
Larki
Islamic Azad University, Parand Branch
author
A.
Riazi
Amirkabir University of Technology
author
text
article
2013
eng
Let A be a bounded linear operator on a Banach space X. We investigate the conditions of existing rank-one operator B such that I+f(A)B is invertible for every analytic function f on sigma(A). Also we compare the invariant subspaces of f(A)B and B. This work is motivated by an operator method on the Banach space ell^2 for solving some PDEs which is extended to general operator space under some conditions in this paper.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
97
106
http://bims.iranjournals.ir/article_239_aa94bb32deb5aba560c323c06fd34102.pdf
On a subclass of multivalent analytic functions associated with an extended fractional differintegral operator
J.-L.
Liu
Department of Mathematics, Yangzhou University
author
text
article
2013
eng
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.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
107
124
http://bims.iranjournals.ir/article_222_b55977251c75b2af4170f508df58c24c.pdf
The two parameter quantum groups
$U_{r,s}(\mathfrak{g})$ associated to generalized Kac-Moody algebra
and their equitable presentation
Q.
Sun
Zhejiang University of Science and Technology, China
author
H.
Li
Zhejiang International Studies University, China
author
text
article
2013
eng
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.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
125
149
http://bims.iranjournals.ir/article_410_9c4af9233d4d3e488f54d9d44c7ea5bd.pdf
Essential norm of generalized composition operators from
weighted Dirichlet or Bloch type spaces to Q_K type spaces
Sh.
Rezaei
Islamic Azad University, Iran
author
H.
Mahyar
Tarbiat Moallem University, Iran
author
text
article
2013
eng
In this paper we obtain lower and upper estimates for the essential norms of generalized composition operators from weighted Dirichlet spaces or Bloch type spaces to $Q_K$ type spaces.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
151
164
http://bims.iranjournals.ir/article_342_7297405479aa435b72d575295ddb0380.pdf
Existence and uniqueness of solutions for a periodic
boundary value problem
A.
Amini Harandi
University of Shahrekord, Iran
author
text
article
2013
eng
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.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
165
173
http://bims.iranjournals.ir/article_343_4afacfa2a4973fe9304d888b866fd3ae.pdf
The Quasi-morphic Property of Group
Q.
Wang
Department of Mathematics and Systems Science, National University of Defense Technology, P.R.China 410073,Changsha, China.
author
K.
Long
Department of Mathematics and Systems Science, National University of Defense Technology ,P.R.China 410073, Changsha, China.
author
L.
Feng
Department of Mathematics and Systems Science, National University of Defense
Technology, P.R.China 410073, Changsha, China.
author
text
article
2013
eng
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.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
175
185
http://bims.iranjournals.ir/article_339_e1fa74b090c7cf943c21d3c24a31908a.pdf
Maximal subsets of pairwise non-commuting elements of some finite p-groups
A.
Azad
Arak University, Iran
author
S.
Fouladi
Kharazmi University, Iran
author
R.
Orfi
Arak University, Iran
author
text
article
2013
eng
Let G be a group. A subset X of G is a set of pairwise noncommuting elements if xy ̸= yx for any two distinct elements x and y in X. If |X| ≥ |Y | for any other set of pairwise non-commuting elements Y in G, then X is said to be a maximal subset of pairwise non-commuting elements. In this paper we determine the cardinality of a maximal subset of pairwise non-commuting elements in any non-abelian p-groups with central quotient of order less than or equal to p3 for any prime number p. As an immediate consequence we give this cardinality for any non-abelian group of order p4.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
187
192
http://bims.iranjournals.ir/article_341_ed95cc075963c4991eb4ff3398515d7c.pdf
$varepsilon$-Simultaneous approximations
of downward sets
H.
Alizadeh
Islamic Aazad University, Marand, Iran
author
Sh.
Rezapour
Azarbaidjan University of Tarbiat Moallem, Iran
author
S.
Vaezpour
Amirkabir University of Technology, Iran
author
text
article
2013
eng
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.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
193
203
http://bims.iranjournals.ir/article_345_3d1cd47063aa5b80dbcd37a8684f8675.pdf
Spacelike hypersurfaces in Riemannian or Lorentzian space forms satisfying L_k(x)=Ax+b
F.
Pashaie
Tarbiat Modares University, Iran
author
S.M.B.
Kashani
Tarbiat Modares University
author
text
article
2013
eng
We study connected orientable spacelike hypersurfaces $x:M^{n}rightarrowM_q^{n+1}(c)$, isometrically immersed into the Riemannian or Lorentzian space form of curvature $c=-1,0,1$, and index $q=0,1$, satisfying the condition $~L_kx=Ax+b$,~ where $L_k$ is the $textit{linearized operator}$ of the $(k+1)$-th mean curvature $H_{k+1}$ of the hypersurface for a fixed integer $0leq k<n$, $A$ is a constant matrix and $b$ is a constant vector. We show that the only hypersurfaces satisfying that condition are hypersurfaces with zero $H_{k+1}$ and constant $H_k$ ( when $cneq 0$ ), open pieces of totally umbilic hypersurfaces and open pieces of the standard Riemannian product of two totally umbilic hypersurfaces.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
1
no.
2013
205
223
http://bims.iranjournals.ir/article_338_564a4b1f52aa0e44c763a92cfc8189b5.pdf