Let F be a field of characteristic different from 2 and let ฯ be an anisotropic six-dimensional quadratic form over F. We study the last open cases in the problem of describing the quadratic forms ฯ such that ฯ becomes isotropic over the function field F ฯ .
Pencils of Quadratic Forms and Hyperelliptic Function Fields
โ Scribed by David B. Leep; Laura Mann Schueller
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 126 KB
- Volume
- 227
- Category
- Article
- ISSN
- 0021-8693
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โฆ Synopsis
Let P k denote the set of equivalence classes of nonsingular pencils of ลฝ . quadratic forms of even order defined over a field k, char k / 2. Let F k denote the set of k-isomorphism classes of hyperelliptic function fields defined over k. We ลฝ . ลฝ . define a map โฝ: P k ยช F k and determine precisely when โฝ is surjective and when โฝ is injective. This extends a method used by A. Weil to study pairs of quadratic forms over finite fields.
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