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arXiv · 2010.13842

Degree 2 cohomological invariants of linear algebraic groups

Alexandre Lourdeaux
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Abstract

The paper deals with the cohomological invariants of smooth and connected linear algebraic groups over an arbitrary field. More precisely, we study degree $2$ invariants with coefficients $\mathbb{Q}/\mathbb{Z}(1)$, that is invariants taking values in the Brauer group. Our main tool is the \'etale cohomology of sheaves on simplicial schemes. We get a description of these invariants for \emph{every} smooth and connected linear groups, in particular for non reductive groups over an imperfect field.

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BibTeXRIS

Alexandre Lourdeaux. 2020-10-26. Degree 2 cohomological invariants of linear algebraic groups. https://doi.org/10.1016/j.jpaa.2022.107059

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