looking for a paper

looking for a paper

[Björn Gohla]

dear colleagues,

i am looking for a paper that i remember reading some years ago, but now seem 
unable to find. 

it contained a detailed discussion of general quotients of categories, i.e., 
where objects can get identified. 

i'd be grateful for any hints anyone can offer.

--
thanks,
björn


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Re: looking for a paper

[Andrée Ehresman]

General quotient categories have been studied by Charles Ehresmann in
the 60's. In particular in his book

"Cat?gories et Structures" (Dunod 1965), Chapter III, which takes back
results from

"Cohomologie ? valeurs dans une cat?gorie dominee" (1964) and other
articles which are reprinted in

"Charles Ehresmann: Oeuvres completes et commentees" Part III-2, freely
downloadable from

http://ehres.pagesperso-orange.fr

Best

Andree





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Re: looking for a paper

[Marco Grandis]

Might be this:
M.A. Bednarczyk, A.M. Borzyszkowski and W. Pawlowski, Generalized congruences-epimorphisms in Cat, 
Theory Appl. Categ. 5 (1999), No. 11, 266-280.

Regards, Marco

On 15/giu/2016, at 19.49, Björn Gohla wrote:

> dear colleagues,
> 
> i am looking for a paper that i remember reading some years ago, but now seem 
> unable to find. 
> 
> it contained a detailed discussion of general quotients of categories, i.e., 
> where objects can get identified. 
> 
> i'd be grateful for any hints anyone can offer.
> 
> --
> thanks,
> björn
> 
> 



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Re: looking for a paper

[tholen]

Hello Björn,

Back in the 70s Reinhard Börger wrote a Master's thesis on such general
quotient categories. His main findings of the time are recorded as
Theorem 2.3 in my commemorative article of his work, available at

http://www.math.yorku.ca/~tholen/ReinhardBoergerTribute.pdf

A shortened version of that article is due to appear in the "Cahiers".

Regards,

Walter


Quoting Björn Gohla <b.gohla@gmx.de>:

> dear colleagues,
>
> i am looking for a paper that i remember reading some years ago, but now seem
> unable to find.
>
> it contained a detailed discussion of general quotients of categories, i.e.,
> where objects can get identified.
>
> i'd be grateful for any hints anyone can offer.
>
> --
> thanks,
> björn
>




[For admin and other information see: http://www.mta.ca/~cat-dist/ ]

Re: looking for a paper

[Björn Gohla]

On Thursday 16 June 2016 22:14:36 Marco Grandis wrote:
> Might be this:
> M.A. Bednarczyk, A.M. Borzyszkowski and W. Pawlowski, Generalized
> congruences-epimorphisms in Cat, Theory Appl. Categ. 5 (1999), No. 11,
> 266-280.
[...]

that's exactly the one. thanks.


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