Subject: Re: two postings Date: Fri, 17 Oct 2003 15:44:03 +0200 From: Rainer Vogt > Subject: query > Date: Thu, 02 Oct 2003 08:55:37 -0400 > From: jim stasheff > > Apparently Graeme's approach to infinite sloop spaces or rather > to one fold loop spaces > has be further abstracted to produce what is known as a `Segal category' > > at a quick glance, it seems to me these are related to Fukaya's A_\infty > > cats > as my approach to \Omega X is related to Graeme's > > anyone seen this worked out or even commented on? > > jim Sorry for the late reply: I have been on the road for two weeks. In our work on the relation between homotopy homomorphisms and the hammock localization of Dwyer and Kan, published in Bol. Soc. Matematica Mexicana 37 (1992), Roland Schwaenzl and I had to consider categories up to coherent homotopies. We started off with A_\infty categories (there are hand-written notes) but realized that we had less troubles with Segal-categories, which we called \Delta -categories, following Segal's notion of a \Delta -space. Both small Segal categories and \Delta-categories can be rectified to strict categories, so there is a direct comparison through the strict version. Take the inclusion of the category CAT of small topologically enriched categories into the category of \Delta categories or A_\infty categories, I am pretty sure that the analysis of the rectification constructions implies that this inclusion is a derived equivalence with respect to suitable model structures on those categories. Rainer Vogt