Normal Hopf subalgebras, depth two and Galois extensions

dc.creatorKadison, Lars
dc.date2004-11-06
dc.date2005-04-06
dc.date.accessioned2026-07-07T05:14:01Z
dc.date.available2026-07-07T05:14:01Z
dc.descriptionLet $S$ be the left $R$-bialgebroid of a depth two extension with centralizer $R$ as defined in math.QA/0108067. We show that the left endomorphism ring of depth two extension, not necessarily balanced, is a left $S$-Galois extension of $A^{\rm op}$. Looking to examples of depth two, we establish that a Hopf subalgebra is normal if and only if it is a Hopf-Galois extension. We find a class of examples of the alternative Hopf algebroids in math.QA/0302325. We also characterize finite weak Hopf-Galois extensions using an alternate Galois canonical mapping with several corollaries: that these are depth two and that surjectivity of the Galois mapping implies its bijectivity.
dc.descriptionsuperseded by my more recent preprints math.QA/0502188 and math.QA/0503194
dc.identifierhttps://arxiv.org/abs/math/0411129
dc.identifierhttp://arxiv.org/abs/math/0411129
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/73123
dc.subjectQuantum Algebra
dc.subjectRings and Algebras
dc.subject16W30 (13B05, 20L05, 16S40, 81R50)
dc.titleNormal Hopf subalgebras, depth two and Galois extensions
dc.typetext

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