Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2511.01440

Lie Algebra Decomposition Classes for Reductive Algebraic Groups in Arbitrary Characteristic

Joel Summerfield
View original source ↗Read source document ↗Export metadata ↓

Abstract

In this paper, we investigate the decomposition classes of the Lie algebras of connected reductive algebraic groups, over algebraically closed fields of arbitrary characteristic. We extend some results proved previously under restrictions on the characteristic, including a formula for the dimension of a decomposition class, and introduce Levi-type decomposition classes to account for some of the difficulties encountered in bad characteristic. We also establish properties of Lusztig--Spaltenstein induction of non-nilpotent orbits, such as parabolic independence, extending the known results for nilpotent orbits. Finally, we determine the covering relation for the closure order on decomposition classes, in the case of good characteristic.

Explore related subjects

math.RTmath.ACmath.AGmath.GRmath.RA

Keep this discovery

BibTeXRIS

Joel Summerfield. 2025-11-03. Lie Algebra Decomposition Classes for Reductive Algebraic Groups in Arbitrary Characteristic. https://arxiv.org/abs/2511.01440

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Quasi-Whittaker supermodules over Lie superalgebras

In this paper, we develop a general theory of quasi-Whittaker supermodules over Lie superalgebras induced from an arbitrary ideal. We determine the quasi-Whittaker vectors in universal supermodules, establish an irreducibility criterion, and classify several families of irreducible supermodules. The odd part produces a new irreducibility phenomenon absent from the Lie algebra setting. As applications, we determine all irreducible quasi-Whittaker supermodules over the $N=1$ super Schr\"odinger algebra and the $N=1$ $\frac{3}{2}$-conformal Galilei superalgebra, and over the complete spectrum-generating superalgebra in a special case.

math.RT↗
arXiv2026

Rankin--Selberg integrals of opposite conductor--one newforms

Let $F$ be a nonarchimedean local field of characteristic zero and let $n\geq2$. For $r=n,n+1$, let $\Pi_r$ be an irreducible tempered representation of ${\rm GL}_r(F)$ of conductor one and with trivial central character. We evaluate the Rankin--Selberg integral of opposite newforms in $\Pi_{n+1}\times \Pi_n$ explicitly and show that its central value is nonzero. As an application, this implies a case of Disegni--Zhang's conjecture on the nonvanishing of local relative characters.

math.RT↗
arXiv2026

Obstructions to Jacobi-Finiteness of Quivers with Potentials

We show that Jacobi-finite potentials need not exist on finite $2$-acyclic quivers. Our main tool is a matrix-valued Golod--Shafarevich--Vinberg inequality for quotients of completed path algebras by finitely many, possibly nonhomogeneous, topological relations. Applied to cyclic derivatives, it yields a potential-dependent obstruction to the finite-dimensionality of completed Jacobian algebras. We then construct a purely quiver-level criterion excluding every Jacobi-finite potential on a given quiver, and exhibit a family of quivers for which every potential has an infinite-dimensional Jacobian algebra.

math.RT↗