Idempotents of compact monothetic semiclosure semigroups
The least cardinal λ such that some (equivalently: every) compact group with weight α admits a dense, pseudocompact subgroup of cardinality λ is denoted by m(α). Clearly, . We show: Theorem 4.12. Let G be Abelian with |G| = γ. If either m(α) ≤ α and m, or α > ω and , then G admits a pseudocompact group topology of weight α. Theorem 4.15. Every connected, pseudocompact Abelian group G with wG = α ≥ ω satisfies . Theorem 5.2(b). If G is divisible Abelian with , then G admits at most -many...
We study when a topological space has a weaker connected topology. Various sufficient and necessary conditions are given for a space to have a weaker Hausdorff or regular connected topology. It is proved that the property of a space of having a weaker Tychonoff topology is preserved by any of the free topological group functors. Examples are given for non-preservation of this property by “nice” continuous mappings. The requirement that a space have a weaker Tychonoff connected topology is rather...
L’indice d’une algèbre de Lie algébrique complexe est la codimension minimale de ses orbites coadjointes. Si est semi-simple, son indice, , est égal à son rang, . Le but de cet article est d’établir une formule générale pour l’indice de pour nilpotent, où est le normalisateur dans du centralisateur de . Plus précisément, on obtient le résultat suivant, conjecturé par D. Panyushev :où est le centre de . Panyushev obtient l’inégalité dans Panyushev 2003 et on montre que la maximalité...