English

The Green ring of a restricted enveloping algebra in characteristic 2

Representation Theory 2025-11-18 v1 Quantum Algebra

Abstract

Let k\Bbbk be an algebraically closed field of characteristic 22 and let fsl(2)\mathfrak{fsl}(2) be the unique, up to isomorphism, 33-dimensional simple Lie algebra over k\Bbbk. Denote by m\mathfrak{m} the minimal 22-envelope of fsl(2)\mathfrak{fsl}(2) and by u(m)\mathfrak{u}(\mathfrak{m}) its corresponding restricted enveloping algebra. The non-isomorphic finite-dimensional indecomposable u(m)\mathfrak{u}(\mathfrak{m})-modules were classified in \cite{ABDF}. In this paper, the Green ring (or representation ring) for u(m)\mathfrak{u}(\mathfrak{m}) is calculated. Also, the semisimplification of the representation category of u(m)\mathfrak{u}(\mathfrak{m}) is determined.

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Cite

@article{arxiv.2511.13345,
  title  = {The Green ring of a restricted enveloping algebra in characteristic 2},
  author = {Nicolás Andruskiewitsch and Dirceu Bagio and Saradia Della Flora and Daiana Flôres},
  journal= {arXiv preprint arXiv:2511.13345},
  year   = {2025}
}