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Twistings and Hopf Galois Extensions

✍ Scribed by Margaret Beattie; Blas Torrecillas

Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
183 KB
Volume
232
Category
Article
ISSN
0021-8693

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✦ Synopsis

A

is also an H-comodule algebra, where the product ) is defined by a) b s Ε½ . Ýa a m b . In this note, we observe that there is a map of pointed sets from the 0 1 twistings of A to the H-measurings from A co H to A and study the set of twistings that map to the trivial measuring. If ArA co H is Galois and H is finitely generated projective, then the twistings that map to the trivial measuring can be described as a set of invertible twisted cocycles: : H m H Βͺ A. An equivalence relation on the set of twisted cocycles corresponds to isomorphism classes of Galois extensions.

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