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arXiv · 1603.02942

Definable maximal cofinitary groups

Vera Fischer·Sy David Friedman·Asger Törnquist
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Abstract

Using countable support iteration of $S$-proper posets, for some appropriate stationary set $S$, we obtain a generic extension of the constructible universe, in which $\mathfrak{b}=\mathfrak{c}=\aleph_2$ and there is a maximal cofinitary group with a $\Pi^1_2$-definable set of generators.

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Vera Fischer, Sy David Friedman, Asger Törnquist. 2016-03-09. Definable maximal cofinitary groups. https://arxiv.org/abs/1603.02942

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