Home /  A First-Order Definition for Campana Points in $\mathbb Q$

Seminar

A First-Order Definition for Campana Points in $\mathbb Q$ July 28, 2022 (03:30 PM PDT - 04:15 PM PDT)
Parent Program:
Location: SLMath: Eisenbud Auditorium, Online/Virtual
Speaker(s) Juan Pablo De Rasis (Ohio State University)
Description No Description
Keywords and Mathematics Subject Classification (MSC)
Primary Mathematics Subject Classification No Primary AMS MSC
Secondary Mathematics Subject Classification No Secondary AMS MSC
Video

A First-Order Definition For Campana Points In $\Mathbb Q$

Abstract/Media

In 2010 J.\ Koenigsmann showed that $\mathbb Z$ is a first-order universally defined subset of $\mathbb Q$; or, equivalently, that the set of non-integer rationals is a diophantine subset of $\mathbb Q$.  Using the same techniques, K.\ Eisentraeger and T.\ Morrison generalized that result to $S$-integers.  Here we give a simpler proof of this, and we obtain a less complex formula which is uniform over all finite sets of primes. We apply our techniques to give an $\forall\exists$ first order definition for Campana points in $\mathbb Q$.

93837?type=thumb A First-Order Definition For Campana Points In $\Mathbb Q$ 534 KB application/pdf

A First-Order Definition For Campana Points In $\Mathbb Q$