English

Quantales, generalised premetrics and free locales

Category Theory 2016-11-03 v4 General Topology

Abstract

Premetrics and premetrisable spaces have been long studied and their topological interrelationships are well-understood. Consider the category Pre{\bf Pre} of premetric spaces and ϵ\epsilon-δ\delta continuous functions as morphisms. The absence of the triangle inequality implies that the faithful functor PreTop{\bf Pre} \to {\bf Top} - where a premetric space is sent to the topological space it generates - is not full. Moreover, the sequential nature of topological spaces generated from objects in Pre{\bf Pre} indicates that this functor is not surjective on objects either. Developed from work by Flagg and Weiss, we illustrate an extension PreP{\bf Pre}\hookrightarrow {\bf P} together with a faithful and surjective on objects left adjoint functor PTop{\bf P} \to {\bf Top} as an extension of PreTop{\bf Pre} \to {\bf Top}. We show this represents an optimal scenario given that PreTop{\bf Pre} \to {\bf Top} preserves coproducts only. The objects in P{\bf P} are metric-like objects valued on value distributive lattices whose limits and colimits we show to be generated by free locales on discrete sets.

Keywords

Cite

@article{arxiv.1502.05351,
  title  = {Quantales, generalised premetrics and free locales},
  author = {J. Bruno and P. Szeptycki},
  journal= {arXiv preprint arXiv:1502.05351},
  year   = {2016}
}

Comments

General Topology, Category Theory, Premetrics, premetrizable spaces, free locale, quantales, continuity spaces, premetrics

R2 v1 2026-06-22T08:32:38.877Z