Invariant Universality for Projective Planes
Invariant Universality for Projective Planes
Author(s): Gianluca PaoliniSubject(s): Economy
Published by: Wydawnictwo Uniwersytetu Jagiellońskiego
Keywords: descriptive set theory; bi-embeddability relation; projective planes; in- variant universality
Summary/Abstract: We continue the work of [1, 2, 3] by analyzing the equivalence relation of bi-embeddability on various classes of countable planes, most notably the class of countable non-Desarguesian projective planes. We use constructions of the author from [13] to show that these equivalence relations are invariantly universal, in the sense of [3], and thus in particular complete analytic. We also introduce a new kind of Borel reducibility relation for standard Borel G-spaces, which requires the preservation of stabilizers, and explain its connection with the notion of full embeddings commonly considered in category theory.
Journal: Reports on Mathematical Logic
- Issue Year: 2023
- Issue No: 58
- Page Range: 15-27
- Page Count: 13
- Language: English