English

Densities of ultraproducts of Boolean algebras

Logic 2016-09-06 v1 General Topology

Abstract

We answer three problems by J. D. Monk on cardinal invariants of Boolean algebras. Two of these are whether taking the algebraic density pi(A), resp. the topological density d(A), of a Boolean algebra A commutes with formation of ultraproducts; the third one compares the number of endomorphisms and of ideals of a Boolean algebra.

Keywords

Cite

@article{arxiv.math/9404226,
  title  = {Densities of ultraproducts of Boolean algebras},
  author = {Sabine Koppelberg and Saharon Shelah},
  journal= {arXiv preprint arXiv:math/9404226},
  year   = {2016}
}