categories - Category Theory list
 help / color / mirror / Atom feed
From: David Leduc <david.leduc6@googlemail.com>
To: Ross Street <ross.street@mq.edu.au>, Aleks Kissinger <aleks0@gmail.com>
Cc: categories@mta.ca
Subject: Re: Dual category and dual object
Date: Sun, 5 Sep 2010 01:50:00 +0000	[thread overview]
Message-ID: <E1OsHMG-0005Ps-5U@mlist.mta.ca> (raw)
In-Reply-To: <3E056346-48EE-4D5C-A2FD-8008A722583A@mq.edu.au>

Could you please spell out what is the unit in Prof (It is not Set, is
it?) and what are the units and counits for dual objects?

Thanks for your help.


On Sun, Sep 5, 2010, Ross Street <ross.street@mq.edu.au> wrote:
> On 05/09/2010, at 5:41 AM, Aleks Kissinger wrote:
>> In the (bi)category Prof of categories and profunctors, the dual of an
>> object is the dual category. Profunctors most certainly came later
>> than the notions of categorical dual and dual objects (or at least
>> their concrete counterparts, dual spaces), so this might just be a
>> happy coincidence.
>
> Very well put!
> I might add that an extra point needed is that Prof is a monoidal bicategory
> where the tensor product is the cartesian product of categories (it is not
> the cartesian product in Prof). And yes, Prof is compact, autonomous,
> rigid, whichever word you prefer, and the dual in Prof of a category A
> is A^{op}. In reading the literature, note that other names for Prof are
> Dist, Bimod and Mod.


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


  parent reply	other threads:[~2010-09-05  1:50 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-04 10:46 David Leduc
2010-09-04 14:46 ` Michael Barr
2010-09-04 16:38 ` Toby Bartels
2010-09-05  0:47   ` Michael Barr
     [not found]   ` <Pine.LNX.4.64.1009042045000.20602@msr03.math.mcgill.ca>
2010-09-05  0:54     ` Toby Bartels
2010-09-04 19:41 ` Aleks Kissinger
     [not found] ` <3E056346-48EE-4D5C-A2FD-8008A722583A@mq.edu.au>
2010-09-05  1:50   ` David Leduc [this message]
     [not found] ` <AANLkTikBACfX_x3DX2pUL6zSGc_5xYoz42q3Gbf3Hpby@mail.gmail.com>
2010-09-05  2:30   ` Aleks Kissinger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=E1OsHMG-0005Ps-5U@mlist.mta.ca \
    --to=david.leduc6@googlemail.com \
    --cc=aleks0@gmail.com \
    --cc=categories@mta.ca \
    --cc=ross.street@mq.edu.au \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).