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Weak Hopf Algebras: I. Integral Theory and C-Structure

✍ Scribed by Gabriella Böhm; Florian Nill; Kornél Szlachányi


Publisher
Elsevier Science
Year
1999
Tongue
English
Weight
324 KB
Volume
221
Category
Article
ISSN
0021-8693

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✦ Synopsis


We give an introduction to the theory of weak Hopf algebras proposed as a coassociati¨e alternative of weak quasi-Hopf algebras. We follow an axiomatic approach keeping as close as possible to the ''classical'' theory of Hopf algebras. The emphasis is put on the new structure related to the presence of canonical subalgebras A L and A R in any weak Hopf algebra A that play the role of non-commutative numbers in many respects. A theory of integrals is developed in which we show how the algebraic properties of A, such as the Frobenius property, or semisimplicity, or innerness of the square of the antipode, are related to the existence of non-degenerate, normalized, or Haar integrals. In case of C*-weak Hopf algebras we prove the existence of a unique Haar measure h g A and of a *


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