Ideals induced by Tsirelson submeasures
We use Tsirelson’s Banach space ([2]) to define an P-ideal which refutes a conjecture of Mazur and Kechris (see [12, 9, 8]).
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Ilijas Farah (1999)
Fundamenta Mathematicae
We use Tsirelson’s Banach space ([2]) to define an P-ideal which refutes a conjecture of Mazur and Kechris (see [12, 9, 8]).
R. Freiwald (1978)
Fundamenta Mathematicae
Ronald Freiwald (1972)
Fundamenta Mathematicae
Vitalij Chatyrko, Yasunao Hattori (2008)
Bulletin of the Polish Academy of Sciences. Mathematics
For each ordinal 1 ≤ α < ω₁ we present separable metrizable spaces , and such that (i) , where f is either trdef or ₀-trsur, (ii) and , (iii) and , and (iv) and . We also show that there exists no separable metrizable space with , and , where A(α) (resp. M(α)) is the absolutely additive (resp. multiplicative) Borel class.
Zajíček, Luděk, Zelený, Miroslav (2005)
Abstract and Applied Analysis
Miroslav Zelený, Luděk Zajíček (2005)
Fundamenta Mathematicae
The main aim of this paper is to give a simpler proof of the following assertion. Let A be an analytic non-σ-porous subset of a locally compact metric space, E. Then there exists a compact non-σ-porous subset of A. Moreover, we prove the above assertion also for σ-P-porous sets, where P is a porosity-like relation on E satisfying some additional conditions. Our result covers σ-⟨g⟩-porous sets, σ-porous sets, and σ-symmetrically porous sets.
J.E. Jayne, C.A. Rogers (1983)
Mathematische Annalen
Dana Scott (1964)
Fundamenta Mathematicae
Robert Vaught (1974)
Fundamenta Mathematicae
Viacheslav I. Malykhin (1999)
Commentationes Mathematicae Universitatis Carolinae
We construct in Bell-Kunen’s model: (a) a group maximal topology on a countable infinite Boolean group of weight and (b) a countable irresolvable dense subspace of . In this model .
G. Godefroy, N. J. Kalton (2007)
Extracta Mathematicae
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