On the Projectivity of module coalgebras
Author:
SiuHung Ng
Journal:
Proc. Amer. Math. Soc. 126 (1998), 31913198
MSC (1991):
Primary 16W30
MathSciNet review:
1469428
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Abstract: In this paper, we derive some criteria for the projectivity of a module coalgebra over a finite dimensional Hopf algebra. In particular, we show that any Hopf algebra over a field of characteristic zero is faithfully flat over its grouplike subHopf algebra. Finally, we prove that if is a finite dimensional subHopf algebra of a Hopf algebra , then is normal in if and only if . This improves a result by S. Montgomery (1993).
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Additional Information
SiuHung Ng
Affiliation:
Department of Mathematics, Rutgers University, New Brunswick, New Jersey 08903
Address at time of publication:
Department of Mathematics, University of California at Santa Cruz, Santa Cruz, California 95064
Email:
shng@math.ucsc.edu
DOI:
http://dx.doi.org/10.1090/S0002993998045997
PII:
S 00029939(98)045997
Received by editor(s):
September 27, 1996
Received by editor(s) in revised form:
April 3, 1997
Communicated by:
Ken Goodearl
Article copyright:
© Copyright 1998
American Mathematical Society
