categories - Category Theory list
 help / color / mirror / Atom feed
From: RONALD BROWN <ronnie.profbrown@btinternet.com>
To: Mike Stay <metaweta@gmail.com>, categories@mta.ca
Subject: Re: Term for edges between graph homomorphisms?
Date: Fri, 17 Mar 2017 18:03:18 +0000 (GMT)	[thread overview]
Message-ID: <E1cpwkL-0003ZC-LP@mlist.mta.ca> (raw)

Mike,

You might find the following paper relevant:

R. Brown, I. Morris, J. Shrimpton and C.D. Wensley, `Graphs of Morphisms of Graphs', Electronic Journal of Combinatorics, A1 of Volume 15(1), 2008. 1-28.

However we do not seem to have given a name to the arrows of GPH(B,C) occurring in

Gph(A \time B, C) \cong Gph(A, GPH(B,C)).

Ronnie

----Original message----
From : metaweta@gmail.com
Date : 16/03/2017 - 16:58 (GMTST)
To : categories@mta.ca
Subject : categories: Term for edges between graph homomorphisms?

If we define a graph to be a tuple (E, V, s: E -> V, t: E -> V), then
the category Gph of graphs and graph homomorphisms is cartesian closed
(in fact, a topos).  For any pair of graphs G, G', there is a "hom
graph" whose vertices are graph homomorphisms from G to G' and whose
edges are things I've been calling "graph shifts".  A graph shift S
between two graph homomorphisms F, F':G -> G' assigns to each vertex g
in G an edge S(g) in G' from F(g) to F'(g).

Is there a more common term for a "graph shift"?
-- 
Mike Stay - metaweta@gmail.com
http://www.cs.auckland.ac.nz/~mike
http://reperiendi.wordpress.com




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


             reply	other threads:[~2017-03-17 18:03 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-17 18:03 RONALD BROWN [this message]
  -- strict thread matches above, loose matches on Subject: below --
2017-03-16 16:58 Mike Stay

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=E1cpwkL-0003ZC-LP@mlist.mta.ca \
    --to=ronnie.profbrown@btinternet.com \
    --cc=categories@mta.ca \
    --cc=metaweta@gmail.com \
    /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).