ambrogio@math.ethz.ch, jfasel@math.ethz.ch
Submission: 2006, Feb 13, revised: 2006, May 29
By simple geometric methods, we calculate the Balmer-Witt groups of the spheres (over a base ring with 2 invertible) up to 2-primary torsion and determine the multiplicative structure of the total graded Witt group. An appendix clarifies an issue concerning the canonicity of coherent Witt groups and transfer morphisms.
2000 Mathematics Subject Classification:
Keywords and Phrases:
Full text: dvi.gz 20 k, dvi 49 k, ps.gz 605 k, pdf.gz 101 k, pdf 124 k.