I am still trying to understand some enriched category theory. Suppose V is a closed symmetric monoidal category that is also locally presentable. Suppose C is a small V-category. I am interested in the category of V-functors from C to V, and, in particular, I want to know that it is locally presentable. Might need some hypotheses on C for this, but I would prefer to avoid hypotheses on the actual functors. This time I have actually looked in Kelly's book and I did not see it, but I confess to finding this subject rough going so might have missed it. On the other hand, my library is closed for the holiday, so I have not looked at Adamek and Rosicky's book on enriched category theory yet. I guess the generators ought to be the representable functors. I know everything is a weighted colimit of representables, but I don't know whether this colimit is filtered enough, nor do I know whether one can get away with weighted colimits instead of ordinary ones. One direction this might go is to develop a theory of locally presentable in an enriched sense, using weighted colimits instead of colimits. I would prefer to avoid that if possible. Happy holidays to all. Mark Hovey
Mark Hovey's letter of 26 Dec - known as Boxing Day in the British-speaking world - suggests that it might be a good idea to develop a theory of local presentability and all that in the context of enriched categories. In fact such a theory was developed in my paper [Structures defined by finite limits in the enriched context I, Cahiers de Top. et Geom. Differentielles 23 (1982), 3 - 42]. Everything works very smoothly; but there are a few annoying misprints, many of which seem to be my own fault. Further developments can be found in [Blackwell-Kelly-Power, Two-dimensional monad theory, J. Pure Appl. Algebra 59 (1989), 1 - 41] and in [Kelly-Power, Adjunctions whose counits are coequalizers and presentations of finitary enriched monads, J. Pure Appl. Algebra 89 (1993), 163 - 179], among other papers of myself and of others; Brian Day, Steve Lack, John Power, and Ross Street have all written on related matters. Please accept, Mark, my best wishes for your future work in this direction. In any case, New Year's Eve is a fine time to send greetings more generally to Bob and all on this Bulletin Board. Warm regards - Max Kelly.
participants (2)
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Mark Hovey -
maxk@maths.usyd.edu.au