English

Games and Scott sentences for positive distances between metric structures

Logic 2022-12-21 v2

Abstract

We develop various Ehrenfeucht-Fra\"{\i}ss\'{e} games for distances between metric structures. We study two forms of distances: pseudometrics stemming from mapping spaces onto each other with some form of approximate isomorphism, and metrics stemming from measuring the distances between two spaces isometrically embedded into a third space. Using an infinitary version of Henson's positive bounded logic with approximations, we form Scott sentences capturing fixed distances to a given space. The Scott sentences of separable spaces are in Lω1ω\mathcal{L}_{\omega_1\omega} for 0-distances and in Lω2ω\mathcal{L}_{\omega_2\omega} for positive distances.

Keywords

Cite

@article{arxiv.2102.00993,
  title  = {Games and Scott sentences for positive distances between metric structures},
  author = {Åsa Hirvonen and Joni Puljujärvi},
  journal= {arXiv preprint arXiv:2102.00993},
  year   = {2022}
}

Comments

This is a generalization of the previous version, based on ideas inspired by other papers on the subject and referee feedback

R2 v1 2026-06-23T22:43:58.453Z