### Ultrafilters and partial products of infinite cyclic groups

by Blass and Shelah. [BsSh:854]

Communications in Algebra, 2005

We consider, for infinite cardinals kappa and
alpha <= kappa^+, the group Pi(kappa,< alpha) of sequences
of integers, of length kappa, with non-zero entries in fewer than
alpha positions. Our main result tells when Pi(kappa,< alpha)
can be embedded in Pi(lambda,< beta) . The proof involves some
set-theoretic results, one about familes of finite sets and one
about families of ultrafilters.

Back to the list of publications