Semigroups on acyclic plane continua

Wilder, B. E.

doi:10.1090/S0002-9939-1971-0276946-6

Semigroups on acyclic plane continua
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by B. E. Wilder PDF

Proc. Amer. Math. Soc. 28 (1971), 587-589 Request permission

Abstract:

It is shown that an acyclic irreducible plane continuum which admits the structure of a topological semigroup is an arc if it has an identity, and is either an arc, is trivial, or is decomposible into an arc if it satisfies ${M^2} = M$. This extends some results of Friedberg and Mahavier concerning semigroups on chainable continua.

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