Depth three towers and Jacobson-Bourbaki correspondence

dc.creatorKadison, Lars
dc.date2007-06-08
dc.date.accessioned2026-07-07T08:04:41Z
dc.date.available2026-07-07T08:04:41Z
dc.descriptionWe introduce a notion of depth three tower of three rings C < B < A as a useful generalization of depth two ring extension. If A = End B_C and B | C is a Frobenius extension, this also captures the notion of depth three for a Frobenius extension in math.RA/0107064 and math.RA/0108067 such that if B | C is depth three, then A | C is depth two (cf. math.QA/0001020). If A, B and C correspond to a tower of subgroups G > H > K via the group algebra over a fixed base ring, the depth three condition is the condition that subgroup K has normal closure K^G contained in H. For a depth three tower of rings, there is a pre-Galois theory for the ring End {}_BA_C and coring (A \otimes_B A)^C involving Morita context bimodules and left coideal subrings. This is applied in the last two sections to a specialization of a Jacobson-Bourbaki correspondence theorem for augmented rings to depth two extensions with depth three intermediate division rings.
dc.description20 pp. (10 pp. supersede math.RA/0703328)
dc.identifierhttps://arxiv.org/abs/0706.1215
dc.identifierhttp://arxiv.org/abs/0706.1215
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/130052
dc.subjectRings and Algebras
dc.subjectCommutative Algebra
dc.subject(Primary) 13B05, 16W30, 81R15; (Secondary) 46L37
dc.titleDepth three towers and Jacobson-Bourbaki correspondence
dc.typetext

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