Vol. 3, No. 3, 2009

Download this article
Download this article For screen
For printing
Recent Issues

Volume 18
Issue 7, 1221–1401
Issue 6, 1039–1219
Issue 5, 847–1038
Issue 4, 631–846
Issue 3, 409–629
Issue 2, 209–408
Issue 1, 1–208

Volume 17, 12 issues

Volume 16, 10 issues

Volume 15, 10 issues

Volume 14, 10 issues

Volume 13, 10 issues

Volume 12, 10 issues

Volume 11, 10 issues

Volume 10, 10 issues

Volume 9, 10 issues

Volume 8, 10 issues

Volume 7, 10 issues

Volume 6, 8 issues

Volume 5, 8 issues

Volume 4, 8 issues

Volume 3, 8 issues

Volume 2, 8 issues

Volume 1, 4 issues

The Journal
About the journal
Ethics and policies
Peer-review process
 
Submission guidelines
Submission form
Editorial board
Editors' interests
 
Subscriptions
 
ISSN: 1944-7833 (e-only)
ISSN: 1937-0652 (print)
 
Author index
To appear
 
Other MSP journals
Weyl groupoids of rank two and continued fractions

Michael Cuntz and István Heckenberger

Vol. 3 (2009), No. 3, 317–340
Abstract

We present a relationship between continued fractions and Weyl groupoids of Cartan schemes of rank two. This allows one to decide easily if a given Cartan scheme of rank two admits a finite root system. We obtain obstructions and sharp bounds for the entries of the Cartan matrices.

Keywords
Cartan matrix, continued fraction, Nichols algebra, Weyl groupoid
Mathematical Subject Classification 2000
Primary: 20F55
Secondary: 11A55, 16W30
Milestones
Received: 1 July 2008
Revised: 19 January 2009
Accepted: 6 March 2009
Published: 1 May 2009
Authors
Michael Cuntz
Fachbereich Mathematik
Universität Kaiserslautern
Postfach 3049
D-67653 Kaiserslautern
Germany
http://www.mathematik.uni-kl.de/~cuntz/en/index.html
István Heckenberger
Mathematisches Institut
Ludwig-Maximilians-Universität München
Theresienstr. 39
D-80333 München
Germany
http://www.mi.uni-koeln.de/~iheckenb/istvane.html