English

A note on Pontryagin duality and continuous logic

Logic 2022-09-20 v2

Abstract

We exhibit Pontryagin duality as a special case of Stone duality in a continuous logic setting. More specifically, given an abelian topological group AA, and F\mathcal F the family (group) of continuous homomorphisms from AA to the circle group T\mathbb T, then, viewing (A,+)(A,+) equipped with the collection F\mathcal F as a continuous logic structure MM, we show that the local type space SF(M)S_\mathcal F(M) is precisely the Pontryagin dual of the group F\mathcal F where the latter is considered as a discrete group. We conclude, using Pontryagin duality (between compact and discrete abelian groups), that SF(M)S_\mathcal F(M) is the Bohr compactification of the topological group AA.

Cite

@article{arxiv.2204.11323,
  title  = {A note on Pontryagin duality and continuous logic},
  author = {Nicolas Chavarria and Anand Pillay},
  journal= {arXiv preprint arXiv:2204.11323},
  year   = {2022}
}

Comments

11 pages