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arXiv · 2301.05480

Faithful flatness of Hopf algebras over coideal subalgebras with a bimodule conditional expectation

Julien Bichon
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Abstract

We give a direct and self-contained proof that if $H$ is a Hopf algebra and $A\subset H$ is a right coideal subalgebra such $A$ is a direct summand in $H$ as an $A$-bimodule, then $H$ is faithfully flat as a left and right $A$-module.

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Julien Bichon. 2023-01-13. Faithful flatness of Hopf algebras over coideal subalgebras with a bimodule conditional expectation. https://arxiv.org/abs/2301.05480

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