Year: 2026
Type: preprint
Abstract: A central object in the theory of proof complexity generators is Krajicek's local witness model. We construct a new such model as a definable ultrapower using a definable version of a selective ultrafilter over a model of arithmetic. We transfer some set theory of combinatorial ultrafilters to the definable nonstandard setting.
Source: arXiv (Cornell University)
Authors: Heil, Johannes, Müller, Moritz
Institution: University of Passau
Language: English
Subfield: Geometry and Topology
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221771780