From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5434 Path: news.gmane.org!not-for-mail From: John Baez Newsgroups: gmane.science.mathematics.categories Subject: quantum groups in physics Date: Mon, 28 Dec 2009 15:40:28 -0800 Message-ID: Reply-To: John Baez NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1262182208 11395 80.91.229.12 (30 Dec 2009 14:10:08 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 30 Dec 2009 14:10:08 +0000 (UTC) To: categories Original-X-From: categories@mta.ca Wed Dec 30 15:10:00 2009 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 1NPzE7-0007Ij-Ue for gsmc-categories@m.gmane.org; Wed, 30 Dec 2009 15:08:40 +0100 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1NPyjI-0001HW-1R for categories-list@mta.ca; Wed, 30 Dec 2009 09:36:48 -0400 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5434 Archived-At: Andre Joyal writes: The theory of quantum groups is mathematically very interesting but it has > no applications that I know to real quantum physics... The fractional quantum Hall effect is a strange effect that occurs when a thin film of superconducting material is put in a transverse magnetic field. The 1998 Nobel Prize in physics was awarded for its discovery and explanation: http://nobelprize.org/nobel_prizes/physics/laureates/1998/press.html I think it's becoming pretty widely accepted that Chern-Simons theory is a good description of the fractional quantum Hall effect. See for example: http://guava.physics.uiuc.edu/~nigel/courses/569/Essays_2002/files/vetsigian.pdf This is a question that experiment will ultimately decide. On the other hand, it's been known in theoretical physics ever since the work of Witten, Reshetihkin and Turaev that Chern-Simons theory can be described in a purely algebraic way using quantum groups! So, people interested in the fractional quantum Hall effect are learning about quantum groups. But interestingly, more important than the quantum group itself is its category of representations, which is a modular tensor category. So in fact we're seeing a nice interplay between experimental condensed matter physics and work on quantum groups and modular tensor categories. But this is not really surprising, since quantum groups and modular tensor categories arose from work on physics. Attempts to use these ideas to build quantum computers are still speculative: http://en.wikipedia.org/wiki/Topological_quantum_computer I can give lots more references if anyone wants. Best, jb [For admin and other information see: http://www.mta.ca/~cat-dist/ ]