From: James Stasheff <jds@math.upenn.edu>
To: Categories <categories@mta.ca>
Subject: Re: Partial answer to Jean Benabou
Date: Sat, 14 Jan 2006 21:03:20 -0500 (EST) [thread overview]
Message-ID: <Pine.GSO.4.58.0601142102430.5113@hans.math.upenn.edu> (raw)
In-Reply-To: <E1EwqpI-0003Ar-TO@mailserv.mta.ca>
see also Drinfeld's paper onthe arXiv @2002 on DG categories
Jim Stasheff jds@math.upenn.edu
Home page: www.math.unc.edu/Faculty/jds
As of July 1, 2002, I am Professor Emeritus at UNC and
I will be visiting U Penn but for hard copy
the relevant address is:
146 Woodland Dr
Lansdale PA 19446 (215)822-6707
On Wed, 11 Jan 2006, Andree Ehresmann wrote:
>
> In answer to the question raised by Jean:
>
> >if C is a category, what does one need to assume on a subcategory
> V of C to be able to construct an analogous C/V and what structure does
> it inherit ?
>
> Charles Ehresmann had studied the problem of the existence of a quotient =
> (or at
> least 'quasi-quotient') category of a category by a sub-category, which h=
> ad led
> to the introduction of the notion of a "proper subcategory" (generalizing
> distinguished sub-groups). His results, summarized in a Note (CRAS Paris=
> 260,
> 2116) are developed in the paper on non-abelian cohomology "Cohomologie a
> valeurs dans une categorie dominee" (Collloque Topologie Bruxelles, CBRM =
> 1866)
> . Both papers are reprinted in "Charles Ehresmann: Oeuvres completes et
> commentees" Part III-2 (and partially taken back in his book "Categories =
> et
> structures", Dunod 1965).
> With all my best wishes
> Andree Ehresmann.
>
>
>
>
prev parent reply other threads:[~2006-01-15 2:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-11 18:00 Andree Ehresmann
2006-01-15 2:03 ` James Stasheff [this message]
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