Non-uniformizable sets of second projective level with countable cross-sections in the form of Vitali classes
Izvestiya. Mathematics , Tome 82 (2018) no. 1, pp. 61-90
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We use a countable-support product
of invariant Jensen's forcing notions
to define a model of $\mathbf{ZFC}$ set theory
in which the uniformization principle fails
for some planar $\varPi_2^1$ set all of whose
vertical cross-sections are countable sets
and, more specifically, Vitali classes.
We also define a submodel of that model, in which
there exists a countable $\varPi_2^1$
sequence of Vitali classes $P_n$ whose
union $\bigcup_nP_n$ is not a countable set.
Of course, the axiom of choice fails in this submodel.
Keywords:
uniformization, forcing
Mots-clés : Vitali classes.
Mots-clés : Vitali classes.
@article{IM2_2018_82_1_a3,
author = {V. G. Kanovei and V. A. Lyubetsky},
title = {Non-uniformizable sets of second projective level with countable cross-sections in the form of {Vitali} classes},
journal = {Izvestiya. Mathematics },
pages = {61--90},
publisher = {mathdoc},
volume = {82},
number = {1},
year = {2018},
language = {en},
url = {http://geodesic.mathdoc.fr/item/IM2_2018_82_1_a3/}
}
TY - JOUR AU - V. G. Kanovei AU - V. A. Lyubetsky TI - Non-uniformizable sets of second projective level with countable cross-sections in the form of Vitali classes JO - Izvestiya. Mathematics PY - 2018 SP - 61 EP - 90 VL - 82 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/IM2_2018_82_1_a3/ LA - en ID - IM2_2018_82_1_a3 ER -
%0 Journal Article %A V. G. Kanovei %A V. A. Lyubetsky %T Non-uniformizable sets of second projective level with countable cross-sections in the form of Vitali classes %J Izvestiya. Mathematics %D 2018 %P 61-90 %V 82 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_2018_82_1_a3/ %G en %F IM2_2018_82_1_a3
V. G. Kanovei; V. A. Lyubetsky. Non-uniformizable sets of second projective level with countable cross-sections in the form of Vitali classes. Izvestiya. Mathematics , Tome 82 (2018) no. 1, pp. 61-90. http://geodesic.mathdoc.fr/item/IM2_2018_82_1_a3/