scholarly journals Maximal subsemigroups of the semigroup of all mappings on an infinite set

2014 ◽  
Vol 367 (3) ◽  
pp. 1911-1944 ◽  
Author(s):  
J. East ◽  
J. D. Mitchell ◽  
Y. Péresse
Keyword(s):  
Maximal Subsemigroups ◽  
Infinite Set

Maximal subsemigroups of some semigroups of order-preserving mappings on a countably infinite set

2017 ◽  
Vol 29 (4) ◽  
Author(s):  
Tiwadee Musunthia ◽  
Jörg Koppitz
Keyword(s):  
Natural Numbers ◽  
Maximal Subsemigroups ◽  
Countably Infinite ◽  
Infinite Set

AbstractIn this paper, we study the maximal subsemigroups of several semigroups of order-preserving transformations on the natural numbers and the integers, respectively. We determine all maximal subsemigroups of the monoid of all order-preserving injections on the set of natural numbers as well as on the set of integers. Further, we give all maximal subsemigroups of the monoid of all bijections on the integers. For the monoid of all order-preserving transformations on the natural numbers, we classify also all its maximal subsemigroups, containing a particular set of transformations.

scholarly journals Baer–Levi semigroups of linear transformations

2004 ◽  
Vol 134 (3) ◽  
pp. 477-499 ◽  
Author(s):  
Suzana Mendes-Gonçalves ◽  
R. P. Sullivan
Keyword(s):  
Vector Space ◽  
Dimensional Vector ◽  
Linear Transformations ◽  
Dimensional Vector Space ◽  
Infinite Dimensional ◽  
Basic Properties ◽  
Maximal Subsemigroups ◽  
Linear Version ◽  
Infinite Set

Given an infinite-dimensional vector space V, we consider the semigroup GS (m, n) consisting of all injective linear α: V → V for which codim ran α = n, where dim V = m ≥ n ≥ ℵ0. This is a linear version of the well-known Baer–Levi semigroup BL (p, q) defined on an infinite set X, where |X| = p ≥ q ≥ ℵ0. We show that, although the basic properties of GS (m, n) are the same as those of BL (p, q), the two semigroups are never isomorphic. We also determine all left ideals of GS (m, n) and some of its maximal subsemigroups; in this, we follow previous work on BL (p, q) by Sutov and Sullivan as well as Levi and Wood.

scholarly journals INJECTIVE TRANSFORMATIONS WITH EQUAL GAP AND DEFECT

2009 ◽  
Vol 79 (2) ◽  
pp. 327-336 ◽  
Author(s):  
JINTANA SANWONG ◽  
R. P. SULLIVAN
Keyword(s):  
Inverse Semigroup ◽  
Green’S Relations ◽  
Maximal Subsemigroups ◽  
Green's Relations ◽  
Algebraic Properties ◽  
Symmetric Inverse Semigroup ◽  
Infinite Set

AbstractSuppose that X is an infinite set and I(X) is the symmetric inverse semigroup defined on X. If α∈I(X), we let dom α and ran α denote the domain and range of α, respectively, and we say that g(α)=|X/dom α| and d(α)=|X/ran α| is the ‘gap’ and the ‘defect’ of α, respectively. In this paper, we study algebraic properties of the semigroup $A(X)=\{\alpha \in I(X)\mid g(\alpha )=d(\alpha )\}$. For example, we describe Green’s relations and ideals in A(X), and determine all maximal subsemigroups of A(X) when X is uncountable.

scholarly journals On Maximal Subsemigroups of Partial Baer-Levi Semigroups

2011 ◽  
Vol 2011 ◽  
pp. 1-14
Author(s):  
Boorapa Singha ◽  
Jintana Sanwong
Keyword(s):  
Inverse Semigroup ◽  
Maximal Subsemigroups ◽  
Symmetric Inverse Semigroup ◽  
Infinite Set

Suppose thatXis an infinite set with|X|≥q≥ℵ0andI(X)is the symmetric inverse semigroup defined onX. In 1984, Levi and Wood determined a class of maximal subsemigroupsMA(using certain subsetsAofX) of the Baer-Levi semigroupBL(q)={α∈I(X):domα=Xand|X∖Xα|=q}. Later, in 1995, Hotzel showed that there are many other classes of maximal subsemigroups ofBL(q), but these are far more complicated to describe. It is known thatBL(q)is a subsemigroup of the partial Baer-Levi semigroupPS(q)={α∈I(X):|X∖Xα|=q}. In this paper, we characterize all maximal subsemigroups ofPS(q)when|X|>q, and we extendMAto obtain maximal subsemigroups ofPS(q)when|X|=q.

scholarly journals Maximal subsemigroups containing a particular semigroup

2014 ◽  
Vol 64 (6) ◽  
Author(s):  
Jörg Koppitz ◽  
Tiwadee Musunthia
Keyword(s):  
Natural Numbers ◽  
Finitely Generated ◽  
Maximal Subsemigroups ◽  
Infinite Set

AbstractWe characterize maximal subsemigroups of the monoid T(X) of all transformations on the set X = ℕ of natural numbers containing a given subsemigroup W of T(X) such that T(X) is finitely generated over W. This paper gives a contribution to the characterization of maximal subsemigroups on the monoid of all transformations on an infinite set.

scholarly journals A Note on On-Line Ramsey Numbers for Some Paths

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 735
Author(s):  
Tomasz Dzido ◽  
Renata Zakrzewska
Keyword(s):  
Ramsey Number ◽  
Ramsey Numbers ◽  
Minimum Number ◽  
On Line ◽  
Infinite Set ◽  
Do So

We consider the important generalisation of Ramsey numbers, namely on-line Ramsey numbers. It is easiest to understand them by considering a game between two players, a Builder and Painter, on an infinite set of vertices. In each round, the Builder joins two non-adjacent vertices with an edge, and the Painter colors the edge red or blue. An on-line Ramsey number r˜(G,H) is the minimum number of rounds it takes the Builder to force the Painter to create a red copy of graph G or a blue copy of graph H, assuming that both the Builder and Painter play perfectly. The Painter’s goal is to resist to do so for as long as possible. In this paper, we consider the case where G is a path P4 and H is a path P10 or P11.

Density of sets with missing differences and applications

2021 ◽  
Vol 71 (3) ◽  
pp. 595-614
Author(s):  
Ram Krishna Pandey ◽  
Neha Rai
Keyword(s):  
Number Theory ◽  
Asymptotic Density ◽  
Theory Problem ◽  
Distance Graphs ◽  
Positive Integers ◽  
Infinite Set

Abstract For a given set M of positive integers, a well-known problem of Motzkin asks to determine the maximal asymptotic density of M-sets, denoted by μ(M), where an M-set is a set of non-negative integers in which no two elements differ by an element in M. In 1973, Cantor and Gordon find μ(M) for |M| ≤ 2. Partial results are known in the case |M| ≥ 3 including some results in the case when M is an infinite set. Motivated by some 3 and 4-element families already discussed by Liu and Zhu in 2004, we study μ(M) for two families namely, M = {a, b,a + b, n(a + b)} and M = {a, b, b − a, n(b − a)}. For both of these families, we find some exact values and some bounds on μ(M). This number theory problem is also related to various types of coloring problems of the distance graphs generated by M. So, as an application, we also study these coloring parameters associated with these families.

An Infinite Set of Heron Triangles with Two Rational Medians

1997 ◽  
Vol 104 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Ralph H. Buchholz ◽  
Randall L. Rathbun
Keyword(s):  
Infinite Set

scholarly journals Time and Life in the Relational Universe: Prolegomena to an Integral Paradigm of Natural Philosophy

Philosophies ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 30 ◽  
Author(s):  
Abir Igamberdiev
Keyword(s):  
Probability Function ◽  
Natural Philosophy ◽  
Natural World ◽  
Spatiotemporal Structure ◽  
Internal Logic ◽  
Decision Making System ◽  
Relational Domains ◽  
Relational Order ◽  
Infinite Set ◽  
The Universe

Relational ideas for our description of the natural world can be traced to the concept of Anaxagoras on the multiplicity of basic particles, later called “homoiomeroi” by Aristotle, that constitute the Universe and have the same nature as the whole world. Leibniz viewed the Universe as an infinite set of embodied logical essences called monads, which possess inner view, compute their own programs and perform mathematical transformations of their qualities, independently of all other monads. In this paradigm, space appears as a relational order of co-existences and time as a relational order of sequences. The relational paradigm was recognized in physics as a dependence of the spatiotemporal structure and its actualization on the observer. In the foundations of mathematics, the basic logical principles are united with the basic geometrical principles that are generic to the unfolding of internal logic. These principles appear as universal topological structures (“geometric atoms”) shaping the world. The decision-making system performs internal quantum reduction which is described by external observers via the probability function. In biology, individual systems operate as separate relational domains. The wave function superposition is restricted within a single domain and does not expand outside it, which corresponds to the statement of Leibniz that “monads have no windows”.

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