Vol. 231, No. 1, 2007

Download this article
Download this article. For screen
For printing
Recent Issues
Vol. 332: 1  2
Vol. 331: 1  2
Vol. 330: 1  2
Vol. 329: 1  2
Vol. 328: 1  2
Vol. 327: 1  2
Vol. 326: 1  2
Vol. 325: 1  2
Online Archive
Volume:
Issue:
     
The Journal
About the journal
Ethics and policies
Peer-review process
 
Submission guidelines
Submission form
Editorial board
Officers
 
Subscriptions
 
ISSN 1945-5844 (electronic)
ISSN 0030-8730 (print)
 
Special Issues
Author index
To appear
 
Other MSP journals
Hopfish algebras

Xiang Tang, Alan Weinstein and Chenchang Zhu

Vol. 231 (2007), No. 1, 193–216
Abstract

We introduce a notion of “hopfish algebra” structure on an associative algebra, allowing the structure morphisms (coproduct, counit, antipode) to be bimodules rather than algebra homomorphisms. We prove that quasi-Hopf algebras are hopfish algebras. We find that a hopfish structure on the algebra of functions on a finite set G is closely related to a “hypergroupoid” structure on G. The Morita theory of hopfish algebras is also discussed.

Keywords
Hopf algebra, hopfish algebra, groupoid, bimodule, Morita equivalence, hypergroupoid
Mathematical Subject Classification 2000
Primary: 16W30
Secondary: 81R50
Milestones
Received: 2 November 2005
Accepted: 10 April 2006
Published: 1 May 2007
Authors
Xiang Tang
Department of Mathematics
Washington University
St. Louis, MO 63130
United States
Alan Weinstein
Department of Mathematics
University of California
Berkeley, CA 94720
United States
Chenchang Zhu
Institut Fourier
Université Joseph Fourier Grenoble I
100, rue des Maths - BP 74
38402 Saint Martin d’Hères Cedex
France