Table of Contents
ISRN Algebra
Volume 2013, Article ID 793637, 5 pages
Research Article

On Hopf-Cyclic Cohomology and Cuntz Algebra

1Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
2Mathematical Institute, Polish Academy of Sciences, Śniadeckich 8, 00-956 Warsaw, Poland

Received 30 April 2013; Accepted 30 May 2013

Academic Editors: V. K. Dobrev, V. Drensky, M. Ladra, M. Przybylska, and P.-H. Zieschang

Copyright © 2013 Andrzej Sitarz. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We demonstrate that Hopf cyclic cocycles, that is, cyclic cocycles with coefficients in stable anti-Yetter-Drinfeld modules, arise from invariant traces on certain ideals of Cuntz-type extension of the algebra.