- Tytuł:
- On quasi-p-bounded subsets
- Autorzy:
-
Sanchis, M.
Tamariz-Mascarúa, A. - Powiązania:
- https://bibliotekanauki.pl/articles/965880.pdf
- Data publikacji:
- 1999
- Wydawca:
- Polska Akademia Nauk. Instytut Matematyczny PAN
- Tematy:
-
free ultrafilter
P-point
(quasi)-p-pseudocompact space
Rudin-Keisler pre-order
p-limit point
(quasi)-p-bounded subset
bounded subset - Opis:
- The notion of quasi-p-boundedness for p ∈ $ω^*$ is introduced and investigated. We characterize quasi-p-pseudocompact subsets of β(ω) containing ω, and we show that the concepts of RK-compatible ultrafilter and P-point in $ω^*$ can be defined in terms of quasi-p-pseudocompactness. For p ∈ $ω^*$, we prove that a subset B of a space X is quasi-p-bounded in X if and only if B × $P_{RK}(p)$ is bounded in X × $P_{RK}(p)$, if and only if $cl_{β(X × P_{RK}(p))}(B× P_{RK}(p)) = cl_{βX} B × β(ω)$, where $P_{RK}(p)$ is the set of Rudin-Keisler predecessors of p.
- Źródło:
-
Colloquium Mathematicum; 1999, 80, 2; 175-189
0010-1354 - Pojawia się w:
- Colloquium Mathematicum
- Dostawca treści:
- Biblioteka Nauki
Artykuł