From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5472 Path: news.gmane.org!not-for-mail From: Vaughan Pratt Newsgroups: gmane.science.mathematics.categories Subject: Re: Quantum computation and categories Date: Mon, 04 Jan 2010 00:12:34 -0800 Message-ID: References: Reply-To: Vaughan Pratt NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1262659695 10597 80.91.229.12 (5 Jan 2010 02:48:15 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 5 Jan 2010 02:48:15 +0000 (UTC) To: categories Original-X-From: categories@mta.ca Tue Jan 05 03:48:08 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from mailserv.mta.ca ([138.73.1.1]) by lo.gmane.org with esmtp (Exim 4.50) id 1NRzSq-0002L9-EZ for gsmc-categories@m.gmane.org; Tue, 05 Jan 2010 03:48:08 +0100 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1NRyxY-0007S0-Ol for categories-list@mta.ca; Mon, 04 Jan 2010 22:15:48 -0400 In-Reply-To: Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5472 Archived-At: John Baez wrote: > (The infinite-dimensional case would introduce extra wrinkles, like > unbounded self-adjoint operators. It's possible that only after we treat > this case correctly can we declare that we know what's going on. Perhaps > trying to treat both unitary and self-adjoint operators as morphisms in the > same category is simply a bad idea. There are a lot of options worth > exploring.) How about starting with rigged Hilbert space? If anything can restore your dagger that should. There's even a Wikipedia article on it; something on dagger categories would be a useful addition to that article. Vaughan [For admin and other information see: http://www.mta.ca/~cat-dist/ ]