English

Comparing invariants of SK1

Algebraic Geometry 2010-03-19 v2 K-Theory and Homology

Abstract

In this text, we compare several invariants of the reduced Whitehead group SK1 of a central simple algebra. For biquaternion algebras, we compare a generalised invariant of Suslin as constructed by the author in a previous article to an invariant introduced by Knus-Merkurjev-Rost-Tignol. Using explicit computations, we prove these invariants are essentially the same. We also prove the non-triviality of an invariant introduced by Kahn. To obtain this result, we compare Kahn's invariant to an invariant introduced by Suslin in 1991 which is non-trivial for Platonov's examples of non-trivial SK1. We also give a formula for the value on the centre of the tensor product of two symbol algebras which generalises a formula of Merkurjev for biquaternion algebras.

Cite

@article{arxiv.1003.1654,
  title  = {Comparing invariants of SK1},
  author = {Tim Wouters},
  journal= {arXiv preprint arXiv:1003.1654},
  year   = {2010}
}

Comments

26 pages

R2 v1 2026-06-21T14:55:05.737Z