Generalized Arf invariants and reduced power operations in cyclic homology

dc.creatorWolters, Paul M. H.
dc.date2005-03-24
dc.date.accessioned2026-07-07T05:18:21Z
dc.date.available2026-07-07T05:18:21Z
dc.descriptionIn this thesis we consider two constructions generalizing the classical Arf invariant. In the first construction an $ε$-symmetric quadratic form over a ring with involution $R$ is lifted to an $ε(1+T)$-symmetric quadratic form over the ring of formal power series $R[[T]]$ with involution mapping $T$ to $\frac{-T}{1+T}$. The discriminant of this form can be viewed as the classical Arf invariant $ω_1$ of the original form, and the Hasse-Witt invariant of this form gives rise to a `secondary' Arf invariant $ω_2$, which is defined on the kernel of $ω_1$. The second construction yields an invariant $Υ$ which is defined on quadratic forms for which the underlying symmetric form is standard. It takes values in a quotient of quaternionic homology $HQ_1(R)$ which is defined using natural operations on $HQ_1$. In the case of a commutative ring $Υ$ agrees with $(ω_1,ω_2)$. The invariant $Υ$ is well suited for computations. In particular we prove that it is faithful if $R$ is the group ring over GF(2) of a group with two ends.
dc.description129 pages; september 1990 PhD thesis
dc.identifierhttps://arxiv.org/abs/math/0503538
dc.identifierhttp://arxiv.org/abs/math/0503538
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/74634
dc.subjectRings and Algebras
dc.subjectAlgebraic Topology
dc.subjectPrimary 11E70; Secondary 19G24; 19G38
dc.titleGeneralized Arf invariants and reduced power operations in cyclic homology
dc.typetext

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