- Tytuł:
- On open maps of Borel sets
- Autorzy:
- Ostrovsky, A.
- Powiązania:
- https://bibliotekanauki.pl/articles/1208391.pdf
- Data publikacji:
- 1995
- Wydawca:
- Polska Akademia Nauk. Instytut Matematyczny PAN
- Tematy:
-
open maps
Borel sets
analytic sets
space of the first category
space of the second category
Baire space - Opis:
- We answer in the affirmative [Th. 3 or Corollary 1] the question of L. V. Keldysh [5, p. 648]: can every Borel set X lying in the space of irrational numbers ℙ not $G_δ · F_σ$ and of the second category in itself be mapped onto an arbitrary analytic set Y ⊂ ℙ of the second category in itself by an open map? Note that under a space of the second category in itself Keldysh understood a Baire space. The answer to the question as stated is negative if X is Baire but Y is not Baire.
- Źródło:
-
Fundamenta Mathematicae; 1994-1995, 146, 3; 203-213
0016-2736 - Pojawia się w:
- Fundamenta Mathematicae
- Dostawca treści:
- Biblioteka Nauki
Artykuł