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arXiv · 2002.01967

A note on Lie algebra cohomology

Michael J. Larsen·Valery A. Lunts
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Abstract

Given a finite dimensional Lie algebra $L$ let $I$ be the augmentation ideal in the universal enveloping algebra $U(L)$. We study the conditions on $L$ under which the $Ext$-groups $Ext (k,k)$ for the trivial $L$-module $k$ are the same when computed in the category of all $U(L)$-modules or in the category of $I$-torsion $U(L)$-modules. We also prove that the Rees algebra $\oplus _{n\geq 0}I^n$ is Noetherian if and only if $L$ is nilpotent. An application to cohomology of equivariant sheaves is given.

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Michael J. Larsen, Valery A. Lunts. 2020-02-05. A note on Lie algebra cohomology. https://doi.org/10.2140/ant.2021.15.773

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