From: Michael Barr <barr@barrs.org>
To: categories@mta.ca
Subject: Re: Uniform spaces
Date: Wed, 27 Aug 2003 16:21:34 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44.0308271616220.16550-100000@triples.math.mcgill.ca> (raw)
In-Reply-To: <Pine.LNX.4.44.0308271647390.21720-100000@ssh.ihes.fr>
Any study of the category must begin with Isbell's wonderful book on the
subject. Although John's exposition could be difficult, it was not so in
that book. I don't recall about limits and colimits (but they ought to be
easy), but there is a lot of discussion of internal homs (which do not
always exist and are not symmetric when they do). The category is not
cartesian closed. I am pretty sure the forgetful functor to Top has a
left adjoint and therefore preserves limits. It preserves sums for sure,
but not coequalizers since a quotient space of a hausdorff uniform space
can be hausdorff without being completely regular. At least, that is what
I think I remember.
Michael
On Wed, 27 Aug 2003, Tom Leinster wrote:
> Hello,
>
> Does anyone know of any account of the basic properties of the category of
> uniform spaces? I'm after things like (co)limits, cartesian closure, and
> (co)limit-preservation by the forgetful functor to Top. Bourbaki gets me
> some of the way, but his decision not to use categorical language and
> the resulting circumlocutions make it a struggle.
>
> Thanks,
> Tom
>
>
>
>
next prev parent reply other threads:[~2003-08-27 20:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-08-27 14:51 Tom Leinster
2003-08-27 20:21 ` Michael Barr [this message]
2003-08-28 0:49 ` Robert L. Knighten
2003-09-02 20:16 ` Oswald Wyler
2003-08-27 17:13 Peter Freyd
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