scholarly journals On Maximal Ideals of Compact Connected Topological Semigroups

Author(s):  
Phoebe McLaughlin ◽  
Shing S. So ◽  
Haohao Wang

Several results concerning ideals of a compact topological semigroup with can be found in the literature. In this paper, we further investigate in a compact connected topological semigroup how the conditions and affect the structure of ideals of , especially the maximal ideals.

2007 ◽  
Vol 14 (01) ◽  
pp. 167-175 ◽  
Author(s):  
S. Romaguera ◽  
M. Sanchis

By a celebrated theorem of Numakura, a Hausdorff compact topological semigroup with two-sided cancellation is a group which has inverse continuous, i.e., it is a topological group. We improve Numakura's Theorem in the realm of non-Hausdorff topological semigroups. This improvement together with some properties of pseudocompact nature in the field of bitopological spaces is used in order to prove that a T0 paratopological group (G,τ) is a (Hausdorff) pseudocompact topological group if and only if (G, τ ∨ τ-1) is pseudocompact or, equivalently, G is Gδ-dense in the Stone–Čech bicompactification [Formula: see text] of (G, τ, τ-1). We also present a version for paratopological groups of the renowned Comfort–Ross Theorem stating that a topological group is pseudocompact if and only if its Stone–Čech compactification is a topological group.


1983 ◽  
Vol 35 (1) ◽  
pp. 1-32
Author(s):  
F. Dangello ◽  
R. Lindahl

1. Introduction. K. Deleeuw and I. Glicksberg [4] proved that if S and T are commutative topological semigroups with identity, then the Bochner almost periodic compactification of S × T is the direct product of the Bochner almost periodic compactifications of S and T. In Section 3 we consider the semidirect product of two semi topological semigroups with identity and two unital C*-subalgebras and of W(S) and W(T) respectively, where W(S) is the weakly almost periodic functions on S. We obtain necessary and sufficient conditions and for a semidirect product compactification of to exist such that this compactification is a semi topological semigroup and such that this compactification is a topological semigroup. Moreover, we obtain the largest such compactifications.


1978 ◽  
Vol 84 (2) ◽  
pp. 323-336 ◽  
Author(s):  
H. A. M. Dzinotyiweyi

Let S be a (jointly continuous) topological semigroup, C(S) the set of all bounded complex-valued continuous functions on S and M (S) the set of all bounded complex-valued Radon measures on S. Let (S) (or (S)) be the set of all µ ∈ M (S) such that x → │µ│ (x-1C) (or x → │µ│(Cx-1), respectively) is a continuous mapping of S into ℝ, for every compact set C ⊆ S, and . (Here │µ│ denotes the measure arising from the total variation of µ and the sets x-1C and Cx-1 are as defined in Section 2.) When S is locally compact the set Ma(S) was studied by A. C. and J. W. Baker in (1) and (2), by Sleijpen in (14), (15) and (16) and by us in (3). In this paper we show that some of the results of (1), (2), (14) and (15) remain valid for certain non-locally compact S and raise some new problems for such S.


1988 ◽  
Vol 37 (2) ◽  
pp. 247-262 ◽  
Author(s):  
Heneri A.M. Dzinotyiweyi

For a very large class of topological semigroups, we establish lower and upper bounds for the cardinality of the set of left invariant means on the space of left uniformly continuous functions. In certain cases we show that such a cardinality is exactly , where b is the smallest cardinality of the covering of the underlying topological semigroup by compact sets.


Filomat ◽  
2017 ◽  
Vol 31 (19) ◽  
pp. 6205-6210 ◽  
Author(s):  
Bin Zhao ◽  
Changchun Xia ◽  
Kaiyun Wang

In this paper, we introduce a condition (?) on topological semigroups, and prove that every T1 topological semigroup satisfying condition (?) has a bounded complete algebraic prequantale model. On the basis of this result, we also show that every T0 topological semigroup satisfying condition (?) can be embedded into a compact and locally compact sober topological semigroup.


Author(s):  
A. Alinejad ◽  
M. Essmaili ◽  
M. Rostami

In this paper, we introduce and study the notion of quasi-multipliers on a semi-topological semigroup [Formula: see text]. The set of all quasi-multipliers on [Formula: see text] is denoted by [Formula: see text]. First, we study the problem of extension of quasi-multipliers on topological semigroups to its Stone–Čech compactification. Indeed, we prove if [Formula: see text] is a topological semigroup such that [Formula: see text] is pseudocompact, then [Formula: see text] can be regarded as a subset of [Formula: see text] Moreover, with an extra condition we describe [Formula: see text] as a quotient subsemigroup of [Formula: see text] Finally, we investigate quasi-multipliers on topological semigroups, its relationship with multipliers and give some concrete examples.


2002 ◽  
Vol 29 (6) ◽  
pp. 355-359
Author(s):  
Alireza Medghalchi

We study compact and weakly compact multipliers onL(S),L(S)**, andLUC(S)*, where the latter is the dual ofLUC(S). We show that a left cancellative semigroupSis left amenable if and only if there is a nonzero compact (or weakly compact) multiplier onL(S)**. We also prove thatSis left amenable if and only if there is a nonzero compact (or weakly compact) multiplier onLUC(S)*.


1959 ◽  
Vol 11 ◽  
pp. 107-111 ◽  
Author(s):  
I. S. Krule

In a recent paper Mostert and Shields (4) showed that if a space homeomorphic to the non-negative real numbers is a certain type of topological semigroup, then the semigroup must be that of the non-negative real numbers with the usual multiplication. Somewhat earlier Faucett (2) showed that if a compact connected ordered space is a suitably restricted topological semigroup, then it must be both topologically and algebraically the same as the unit interval of real numbers with its usual multiplication.In studying certain binary relations on topological spaces there have become known (see, in particular, Wallace (5) and the author (3)) a number of properties analogous to those possessed by topological semigroups. Because of these analogous properties between relations and semigroups the author was motivated by the general nature of the Faucett and Mostert-Shields results (that is, that the multiplication assumed turned out to be the same as the usual multiplication) to feel that certain relations on a connected ordered space should turn out to be the same as the orders whose order topologies are the topology on the space.


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