The converse to Karpenko's non-ruledness theorem for anisotropic quadratic forms
The converse to Karpenko's non-ruledness theorem for anisotropic quadratic forms
Let be an anisotropic quadratic form over a field . Its first Witt index is the Witt index of after extending scalars to the function field of the projective quadric defined by , and is ruled over when its projective quadric is ruled.
Converse to Karpenko's theorem. If the first Witt index of is greater than , then is ruled over .
Karpenko's theorem says that an anisotropic quadratic form with first Witt index is not ruled. This conjecture proposes the converse and is supported in the source by a proof for quadratic forms of dimension at most .
Progress summary
Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.
Sources & referencesView supporting material
Primary source
Burt Totaro, “The automorphism group of an affine quadric”, arXiv:math/0608094 (2006).
Solutions 0
Sign in to submit a solution.
No solutions have been posted yet.