The classical archipelago is a non-contractible subset of $\mathbb {R}^ 3$ which is
homeomorphic to a disk except at one non-manifold point. Its fundamental group, $\mathscr …

We investigate the fundamental group of Griffithsʼ space, and the first singular homology
group of this space and of the Hawaiian Earring by using (countable) reduced tame words …

It is shown that if $\{H_n\} _ {n\in\omega} $ is a sequence of groups without involutions, with
$1<| H_n|\leq 2^{\aleph_0} $, then the topologist's product modulo the finite words is (up to …

It is shown that the fundamental group of the Griffiths double cone space is isomorphic to
that of the triple cone. More generally if κ is a cardinal such that 2≤ κ≤ 2 ℵ 0 then the κ-fold …

We show a dichotomy for groups of cardinality less than continuum. The number of
homomorphisms from the Hawaiian earring group to such a group G is either the cardinality …

arXiv:1107.1332v1 [math.GR] 7 Jul 2011 Generalized presentations of infinite groups, in
particular of Aut(Fω) Page 1 arXiv:1107.1332v1 [math.GR] 7 Jul 2011 Generalized presentations …

We classify pointed spaces according to the first fundamental group of their reduced
suspension. A pointed space is either of so-called totally path disconnected type or of …