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arXiv · 2008.04539

members of thin $Π_1^0$ classes and generic degrees

Abstract

A $Π^{0}_{1}$ class $P$ is thin if every $Π^{0}_{1}$ subclass $Q$ of $P$ is the intersection of $P$ with some clopen set. In 1993, Cenzer, Downey, Jockusch and Shore initiated the study of Turing degrees of members of thin $Π^{0}_{1}$ classes, and proved that degrees containing no members of thin $Π^{0}_{1}$ classes can be recursively enumerable, and can be minimal degree below {\bf 0}$'$. In this paper, we work on this topic in terms of genericity, and prove that all 2-generic degrees contain no members of thin $Π^{0}_{1}$ classes. In contrast to this, we show that all 1-generic degrees below {\bf 0}$'$ contain members of thin $Π^{0}_{1}$ classes.

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BibTeXRIS

Frank Stephan, Guohua Wu, Bowen Yuan. 2020-08-11. members of thin $Π_1^0$ classes and generic degrees. https://arxiv.org/abs/2008.04539

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