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arXiv · 2008.08953

The discriminant Pfister form of an algebra with involution of capacity four

Karim Johannes Becher·Nicolas Grenier-Boley·Jean-Pierre Tignol
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Abstract

To an orthogonal or unitary involution on a central simple algebra of degree 4, or to a symplectic involution on a central simple algebra of degree 8, we associate a Pfister form that characterises the decomposability of the algebra with involution. In this way we obtain a unified approach to known decomposability criteria for several cases, and a new result for symplectic involutions on degree $8$ algebras in characteristic 2.

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Karim Johannes Becher, Nicolas Grenier-Boley, Jean-Pierre Tignol. 2020-08-20. The discriminant Pfister form of an algebra with involution of capacity four. https://doi.org/10.1007/s11856-024-2647-4

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