Some New Results Concerning Isotropy of Low-dimensional Forms
Let ø and ψ be quadratic forms over a field F of characteristic ≠2. We give an (almost) complete classification of pairs ø, ψ of dimension ≤ 9 such that ø is stably equivalent to ψ. We also study the question when the form ø is isotropic over the function field of ψ. In the case where dim #x00F8; = 9 and dim ψ ≥ 9 we solve this problem completely.
(a) Isotropy of 7-dimensional forms and 8-dimensional forms.
(b) Stable equivalence of 9-dimensional forms.
(c) Isotropy of 10- and 12-dimensional forms.
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