From: Ross Street <street@ics.mq.edu.au>
To: categories@mta.ca
Subject: Re: right adjoint by forgetting relational symbols
Date: Fri, 17 Oct 2008 09:05:06 +1100 [thread overview]
Message-ID: <E1KqqP1-0006PJ-7D@mailserv.mta.ca> (raw)
Right adjoints to algebraic functors are very interesting.
Witt vectors and lambda-rings are key words. See
MR0265348 (42 #258) Tall, D. O.; Wraith, G. C.
Representable functors and operations on rings. Proc. London Math.
Soc. (3) 20 1970 619--643.
MR0789309 (86j:13023) Joyal, André(3-PQ)
$\delta$-anneaux et vecteurs de Witt. (French) [$\delta$-rings and
Witt vectors]
C. R. Math. Rep. Acad. Sci. Canada 7 (1985), no. 3, 177--182.
May not be relevant to your examples!
Regards,
Ross
On 16/10/2008, at 9:19 PM, Gaucher Philippe wrote:
> Thank you for all answers. But they do not give what I want. I am
> looking for
> a -R-I-G-H-T- adjoint, and by comparing the example I have and the
> limit
> theory axiomatizing the category of small categories (for which the
> forgetful
> functor Mod(T)-->Set does not have any right adjoint since it is not
> colimit-preserving),
next reply other threads:[~2008-10-16 22:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-16 22:05 Ross Street [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-10-16 10:19 Gaucher Philippe
2008-10-15 10:03 Gaucher Philippe
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