A note on Lie and Jordan structures of Leavitt path algebras
Huynh Viet Khanh, Le Qui Danh
TL;DR
The paper determines exactly when the Lie algebra $\mathbf{K}_{L_K(E)}$ and the Jordan algebra $\mathbf{S}_{L_K(E)}$ (arising from the Leavitt path algebra $L_K(E)$ with the standard involution) are solvable, building on Herstein’s foundational work and recent classifications. It develops a matrix-algebra with involution framework to derive precise criteria based on the matrix size $n$, the field characteristic, and whether the involution is trivial, then translates these into graph-theoretic conditions for Leavitt path algebras by decomposing $L_K(E)$ into matrix-like ideals. The main contributions are exact solvability and nilpotence indices for various cases: for $\mathbf{K}_{\mathbb{M}_n(\mathcal{A})}$, solvability hinges on $n$ and $(\mathrm{char}(K),\text{involution})$; for $L_K(E)$, solvability of $\mathbf{K}_{L_K(E)}$ (char $2$) occurs precisely when $E$ is a disjoint union of the graphs $E_1$–$E_6$, with index bounds, and (char $\neq2$) when $E$ is a disjoint union of $E_1,E_2,E_4$; analogous criteria are given for the Jordan solvable $\mathbf{S}_{L_K(E)}$ and related structures. These results provide sharp, graph-theoretic criteria for Lie and Jordan solvability in Leavitt path algebras with involution.
Abstract
Let $L_K(E)$ be the Leavitt path algebra of a directed graph $E$ over a field $K$. In this paper, we determine $E$ and $K$ for the Lie algebra $\mathbf{K}_{L_K(E)}$ and the Jordan algebra $\mathbf{S}_{L_K(E)}$ arising from $L_K(E)$ with respect to the standard involution to be solvable.
