We have decided to discontinue the publication of preprints on our preprint server as of 1 March 2024. The publication culture within mathematics has changed so much due to the rise of repositories such as ArXiV (www.arxiv.org) that we are encouraging all institute members to make their preprints available there. An institute's repository in its previous form is, therefore, unnecessary. The preprints published to date will remain available here, but we will not add any new preprints here.
MiS Preprint
128/2006
Adjunction of monoids
Dimitry A. Leites and Vladimir Molotkov
Abstract
Let M and N be monoids considered as categories with the only object. Let f:M-->N and g: N--> M be morphisms of monoids, considered as functors. Let the functor f be left adjoint to g. In 1976, E. Manes, in the book "Algebraic Theories" (Springer), posed the question: Is it true that f (or g) is always an isomorphism? Here we show that the answer is NO.