Cup Products on Hochschild Cohomology of Hopf-Galois Extensions.pdf

Fuente: arXiv
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Main Authors: Liu, Liyu, Ren, Wei, Wang, Shengqiang
Format: Preprint
Published: 2025
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author Liu, Liyu
Ren, Wei
Wang, Shengqiang
author_facet Liu, Liyu
Ren, Wei
Wang, Shengqiang
contents In this paper, we give an explicit chain map, which induces the algebra isomorphism between the Hochschild cohomology ${\bf HH}^{\bullet}(B)$ and the $H$-invariant subalgebra ${\bf H}^{\bullet}(A, B)^{H}$ under two mild hypotheses, where $H$ is a finite dimensional semisimple Hopf algebra and $B$ is an $H$-Galois extension of $A$. In particular, the smash product $B=A\#H$ always satisfies the mild hypotheses. The isomorphism between ${\bf HH}^{\bullet}(A\#H)$ and ${\bf H}^{\bullet}(A, A\#H)^{H}$ generalizes the classical result of group actions. As an application, Hochschild cohomology and cup product of the smash product of the quantum $(-1)$-plane and Kac--Paljutkin Hopf algebra are computed.
format Preprint
id arxiv_https___arxiv_org_abs_2502_01967
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cup Products on Hochschild Cohomology of Hopf-Galois Extensions.pdf
Liu, Liyu
Ren, Wei
Wang, Shengqiang
Rings and Algebras
K-Theory and Homology
Quantum Algebra
In this paper, we give an explicit chain map, which induces the algebra isomorphism between the Hochschild cohomology ${\bf HH}^{\bullet}(B)$ and the $H$-invariant subalgebra ${\bf H}^{\bullet}(A, B)^{H}$ under two mild hypotheses, where $H$ is a finite dimensional semisimple Hopf algebra and $B$ is an $H$-Galois extension of $A$. In particular, the smash product $B=A\#H$ always satisfies the mild hypotheses. The isomorphism between ${\bf HH}^{\bullet}(A\#H)$ and ${\bf H}^{\bullet}(A, A\#H)^{H}$ generalizes the classical result of group actions. As an application, Hochschild cohomology and cup product of the smash product of the quantum $(-1)$-plane and Kac--Paljutkin Hopf algebra are computed.
title Cup Products on Hochschild Cohomology of Hopf-Galois Extensions.pdf
topic Rings and Algebras
K-Theory and Homology
Quantum Algebra
url https://arxiv.org/abs/2502.01967