Title of article :
Abelian torsion groups with a countably compact group topology
Author/Authors :
Castro-Pereira، نويسنده , , Irene and Tomita، نويسنده , , Artur Hideyuki، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2010
Abstract :
Comfort and Remus [W.W. Comfort, D. Remus, Abelian torsion groups with a pseudocompact group topology, Forum Math. 6 (3) (1994) 323–337] characterized algebraically the Abelian torsion groups that admit a pseudocompact group topology using the Ulm–Kaplansky invariants.
w, under a condition weaker than the Generalized Continuum Hypothesis, that an Abelian torsion group (of any cardinality) admits a pseudocompact group topology if and only if it admits a countably compact group topology. Dikranjan and Tkachenko [D. Dikranjan, M. Tkachenko, Algebraic structure of small countably compact Abelian groups, Forum Math. 15 (6) (2003) 811–837], and Dikranjan and Shakhmatov [D. Dikranjan, D. Shakhmatov, Forcing hereditarily separable compact-like group topologies on Abelian groups, Topology Appl. 151 (1–3) (2005) 2–54] showed this equivalence for groups of cardinality not greater than 2 c .
o show, from the existence of a selective ultrafilter, that there are countably compact groups without non-trivial convergent sequences of cardinality κ ω , for any infinite cardinal κ. In particular, it is consistent that for every cardinal κ there are countably compact groups without non-trivial convergent sequences whose weight λ has countable cofinality and λ > κ .
Keywords :
Countably compact groups , Selective ultrafilters , Ulm–Kaplansky invariants , Torsion group
Journal title :
Topology and its Applications
Journal title :
Topology and its Applications