We first discuss the construction by Pérez-Izquierdo and Shestakov of universal nonassociative enveloping algebras of Malcev algebras. We then describe recent results on explicit structure constants for the universal enveloping algebras (both nonassociative and alternative) of the 4-dimensional solvable Malcev algebra and the 5-dimensional nilpotent Malcev algebra. We include a proof (due to Shestakov) that the universal alternative enveloping algebra of the real 7-dimensional simple Malcev algebra...

Let $G$ be a simple algebraic group over an algebraically closed field $𝕜$ of characteristic 0, and $𝔤=LieG$. Let $(e,h,f)$ be an $𝔰{𝔩}_2$-triple in $𝔤$ with $e$ being a long root vector in $𝔤$. Let $(·,·)$ be the $G$-invariant bilinear form on $𝔤$ with $(e,f)=1$ and let $\chi \in {𝔤}^{*}$ be such that $\chi \left(x\right)=(e,x)$ for all $x\in 𝔤$. Let $𝒮$ be the Slodowy slice at $e$ through the adjoint orbit of $e$ and let $H$ be the enveloping algebra of $𝒮$; see [31]. In this article we give an explicit presentation of $H$ by generators and relations. As a consequence we deduce that $H$ contains an ideal...

Let $X$ be a (generalized) flag manifold of a complex semisimple Lie group $G$. We investigate the problem of constructing a graded star product on $ℛ=R\left(T^{☆}X\right)$ which corresponds to a $G$-equivariant quantization of symbols into twisted differential operators acting on half-forms on $X$. We construct, when $ℛ$ is generated by the momentum functions ${\mu }^x$ for $G$, a preferred choice of $☆$ where ${\mu }^x☆\phi$ has the form ${\mu }^x\phi +\frac{1}{2}\{{\mu }^x,\phi \}t+{\Lambda }^x\left(\phi \right)t^2$. Here ${\Lambda }^x$ are operators on $ℛ$. In the known examples, ${\Lambda }^x$ ($x\ne 0$) is not a differential operator, and so the star product ${\mu }^x☆\phi$...

We determine the length of composition series of projective modules of G-transitive algebras with an Auslander-Reiten component of Euclidean tree class. We thereby correct and generalize a result of Farnsteiner [Math. Nachr. 202 (1999)]. Furthermore we show that modules with certain length of composition series are periodic. We apply these results to G-transitive blocks of the universal enveloping algebras of restricted p-Lie algebras and prove that G-transitive principal blocks only allow components...