Topological features of lax algebras


Abstract: Having as starting point Barr's description of topological spaces as lax algebras for the ultrafilter monad [2], in this paper we present further topological examples of lax algebras - such as quasi-metric spaces, approach spaces and quasi-uniform spaces - and show that, in a suitable setting, the categories of lax algebras have indeed a topological nature. Furthermore, we generalize to this setting known properties of special categories of lax algebras and, extending the construction of Manes [11], we describe the Cech-Stone compactification of lax algebras.