Results 21 to 26 of about 40,053 (26)
Witt groups of Grassmann varieties
, 2012 We compute the total Witt groups of (split) Grassmann varieties, over any regular base X. The answer is a free module over the total Witt ring of X. We provide an explicit basis for this free module, which is indexed by a special class of Young diagrams,
Balmer, Paul, Calmès, Baptiste
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Types of Linkage of Quadratic Pfister Forms
, 2018 Given a field $F$ of positive characteristic $p$, $\theta \in H_p^{n-1}(F)$ and $\beta,\gamma \in F^\times$, we prove that if the symbols $\theta \wedge \frac{d \beta}{\beta}$ and $\theta \wedge \frac{d \gamma}{\gamma}$ in $H_p^n(F)$ share the same ...
Chapman, Adam, Dolphin, Andrew
core
Trace forms of Galois extensions in the presence of a fourth root of unity
, 2003 We study quadratic forms that can occur as trace forms of Galois field extensions L/K, under the assumption that K contains a primitive 4th root of unity. M. Epkenhans conjectured that any such form is a scaled Pfister form.
J. Min, Z. Reichstein, Áč
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Geometric description of the connecting homomorphism for Witt groups
, 2008 We give a geometric setup in which the connecting homomorphism in the localization long exact sequence for Witt groups decomposes as the pull-back to the exceptional fiber of a suitable blow-up followed by a push-forward.Comment: 19 pages, minor details ...
Balmer, Paul, Calmès, Baptiste
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The descent of biquaternion algebras in characteristic two
, 2019 In this paper we associate an invariant to a biquaternion algebra $B$ over a field $K$ with a subfield $F$ such that $K/F$ is a quadratic separable extension and $\operatorname{char}(F)=2$. We show that this invariant is trivial exactly when $B \cong B_0
Barry, Demba +2 more
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Total linkage of quaternion algebras and Pfister forms in characteristic two
, 2016 We study the subfields of quaternion algebras that are quadratic extensions of their center in characteristic 2. We provide examples of the following: two non-isomorphic quaternion algebras that share all their quadratic subfields, two quaternion ...
Chapman, Adam +2 more
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