Remarks on compactifications of pseudofinite groups [article]

Anand Pillay
2015 arXiv   pre-print
We discuss the Bohr compactification of a pseudofinite group, motivated by a question of Boris Zilber. Basically referring to results in the literature we point out (i) the Bohr compactification of an ultraproduct of finite simple groups is trivial, and (ii) the "definable" Bohr compactification of any pseudofinite group G, relative to a nonstandard model of set theory in which it is definable, is commutative-by-profinite.
arXiv:1509.02895v1 fatcat:abtqusnb7bhnnfrygi5s3qqgzq