Preservation of the Borel class under open-LC functions

• Autorzy: Alexey Ostrovsky
• Języki publikacji: EN

Abstrakty

EN

Let X be a Borel subset of the Cantor set C of additive or multiplicative class α, and f: X → Y be a continuous function onto Y ⊂ C with compact preimages of points. If the image f(U) of every clopen set U is the intersection of an open and a closed set, then Y is a Borel set of the same class α. This result generalizes similar results for open and closed functions.

Kategorie tematyczne

• 54H05: Descriptive set theory (topological aspects of Borel, analytic, projective, etc. sets)
• 54C10: Special maps on topological spaces (open, closed, perfect, etc.)
• 03E15: Descriptive set theory
• 54E40: Special maps on metric spaces

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Fundamenta Mathematicae
• Rocznik: 2011
• Tom: 213
• Numer: 2
• Strony: 191-195

Daty

wydano

2011

Twórcy

autor

Alexey Ostrovsky

• Helmut-Käutner Str. 25, 81739 München, Germany

Identyfikatory

DOI

10.4064/fm213-2-4