All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 38 Next

Displaying 741 – 760 of 925

Showing per page

The Lindelöf property and pseudo- ℵ 1 -compactness in spaces and topological groups

Constancio Hernández, Mihail G. Tkachenko (2008)

Commentationes Mathematicae Universitatis Carolinae

We introduce and study, following Z. Frol’ık, the class ℬ ( 𝒫 ) of regular P -spaces X such that the product X × Y is pseudo- ℵ 1 -compact, for every regular pseudo- ℵ 1 -compact P -space Y . We show that every pseudo- ℵ 1 -compact space which is locally ℬ ( 𝒫 ) is in ℬ ( 𝒫 ) and that every regular Lindelöf P -space belongs to ℬ ( 𝒫 ) . It is also proved that all pseudo- ℵ 1 -compact P -groups are in ℬ ( 𝒫 ) . The problem of characterization of subgroups of ℝ -factorizable (equivalently, pseudo- ℵ 1 -compact) P -groups is considered as well. We give some necessary...

The modular class of a Poisson map

Raquel Caseiro, Rui Loja Fernandes (2013)

Annales de l’institut Fourier

We introduce the modular class of a Poisson map. We look at several examples and we use the modular classes of Poisson maps to study the behavior of the modular class of a Poisson manifold under different kinds of reduction. We also discuss their symplectic groupoid version, which lives in groupoid cohomology.

The Ribes-Zalesskii property of some one relator groups

Gilbert Mantika, Narcisse Temate-Tangang, Daniel Tieudjo (2022)

Archivum Mathematicum

The profinite topology on any abstract group G , is one such that the fundamental system of neighborhoods of the identity is given by all its subgroups of finite index. We say that a group G has the Ribes-Zalesskii property of rank k , or is RZ k with k a natural number, if any product H 1 H 2 ⋯ H k of finitely generated subgroups H 1 , H 2 , ⋯ , H k is closed in the profinite topology on G . And a group is said to have the Ribes-Zalesskii property or is RZ if it is RZ k for any natural number k . In this paper we characterize groups...

Currently displaying 741 – 760 of 925