English

Some notes concerning the homogeneity of Boolean algebras and Boolean spaces

Logic 2007-05-23 v1

Abstract

We consider homogeneity properties of Boolean algebras that have nonprincipal ultrafilters which are countably generated.It is shown that a Boolean algebra B is homogeneous if it is the union of countably generated nonprincipal ultrafilters and has a dense subset D such that for every a in D the relative algebra B restriction a:= {b in B:b <= a} is isomorphic to B. In particular, the free product of countably many copies of an atomic Boolean algebra is homogeneous. Moreover, a Boolean algebra B is homogeneous if it satisfies the following conditions: (i) B has a countably generated ultrafilter, (ii) B is not c.c.c., and (iii) for every a in B setminus {0} there are finitely many automorphisms h_1, ...,h_n of B such that 1=h_1(a) cup ... cup h_n(a).

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Cite

@article{arxiv.math/0211399,
  title  = {Some notes concerning the homogeneity of Boolean algebras and Boolean spaces},
  author = {Stefan Geschke and Saharon Shelah},
  journal= {arXiv preprint arXiv:math/0211399},
  year   = {2007}
}
R2 v1 2026-07-22T16:49:45.175Z