%0 Journal Article %T A study of extremally disconnected topological spaces %A Alexander Arhangel¡¯skii %J Bulletin of Mathematical Sciences %@ 1664-3615 %D 2011 %I Springer %R 10.1007/s13373-011-0001-8 %X We show that if an extremally disconnected space X has a homogeneous compactification, then X is finite. It follows that if a totally bounded topological group has a dense extremally disconnected subspace, then it is finite. The techniques developed in this article also imply that if the square of a topological group G has a dense extremally disconnected subspace, then G is discrete. See also Theorem 3.12. We also establish a sufficient condition for an extremally disconnected topological ring to be discrete (Theorem 3.9). A theorem on the structure of an arbitrary homeomorphism of an extremally disconnected topological group onto itself is proved (see Theorem 3.7 and Corollary 3.8). %K Extremally disconnected %K Compactification %K Topological group %K Dyadic compactum %K Homogeneous space %K Totally bounded group %K Primary 54A25 %K Secondary 54B05 %U http://link.springer.com/article/10.1007/s13373-011-0001-8