Pfister’s theorem for orthogonal involutions of degree 12

Garibaldi, Skip; Quéguiner-Mathieu, Anne

doi:10.1090/S0002-9939-08-09674-3

Pfister’s theorem for orthogonal involutions of degree 12
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by Skip Garibaldi and Anne Quéguiner-Mathieu PDF

Proc. Amer. Math. Soc. 137 (2009), 1215-1222 Request permission

Abstract:

We use the fact that a projective half-spin representation of $\operatorname {Spin}_{12}$ has an open orbit to generalize Pfister’s result on quadratic forms of dimension 12 in $I^3$ to orthogonal involutions.

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