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Explicit calculations in an infinitesimal singular block of SLn

Part of: Lie algebras and Lie superalgebras Linear algebraic groups and related topics

Published online by Cambridge University Press:  10 February 2022

William Hardesty
William Hardesty*
Affiliation:
School of Mathematics and Statistics F07, University of Sydney, Sydney, NSW2006, Australia (william.hardesty@sydney.edu.au)
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Abstract

Let $G= SL_{n+1}$ be defined over an algebraically closed field of characteristic $p > 2$. For each $n \geq 1$, there exists a singular block in the category of $G_1$-modules, which contains precisely $n+1$ irreducible modules. We are interested in the ‘lift’ of this block to the category of $G_1T$-modules. Imposing only mild assumptions on $p$, we will perform a number of calculations in this setting, including a complete determination of the Loewy series for the baby Verma modules and all possible extensions between the irreducible modules. In the case where $p$ is extremely large, we will also explicitly compute the Loewy series for the indecomposable projective modules.

Keywords

representation theoryrestricted Lie algebrasgroup schemesLoewy series

MSC classification

Primary: 20G05: Representation theory
Secondary: 17B45: Lie algebras of linear algebraic groups
Type
Research Article
Information
Proceedings of the Edinburgh Mathematical Society , Volume 65 , Issue 1 , February 2022 , pp. 19 - 52
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Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on Behalf of The Edinburgh Mathematical Society

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