Searcharxiv⌕ Search

arXiv subjects

Roman Lubkov

Publications and source records attributed to Roman Lubkov.

11 recordsLinked to original sources
arXiv2026

Transposed Poisson structure on the Witt-type algebra $\mathcal{W}(a,-1)$: Derivations, Automorphisms, and Rota--Baxter operators

In this paper, we provide a comprehensive study of the structural properties of the transposed Poisson algebra $\mathcal{W}(a,-1)$. We classify several types of linear maps, including derivations, local derivations, quasi-derivations, and $\delta$-derivations, showing that non-trivial $\delta$-derivations exist only for $\delta=1$ and $\delta=\frac{1}{2}$. Furthermore, we describe the groups of automorphisms, local automorphisms, 2-local automorphisms, and quasi-automorphisms. We also investigate Rota--Baxter operators of weight $1$ on $\mathcal{W}(a,-1)$. Specifically, we classify operators that are homogeneous with respect to both the standard $\mathbf{Z}$-grading and a $\mathbf{Z}_2$-grading, establishing a rigidity result for the latter case. Finally, we classify all $\mathbf{W}$-compatible Novikov--Poisson structures, demonstrating that the associative product on the Witt algebra is universally compatible with its known Novikov structures.

math.RA↗
arXiv2026

The algebraic and geometric classification of $\delta$-Novikov algebras

The notion of $\delta$-Novikov algebras was introduced recently as a generalization of Novikov and bicommutative algebras. It looks like $\delta$-Novikov algebras have a richer structure than Novikov algebras. So, unlike Novikov algebras, they have a $2$-dimensional simple algebra for $\delta=-1.$ The present paper is dedicated to the study of $3$-dimensional $\delta$-Novikov algebras for $\delta \notin \big\{0,1\big\}.$ The algebraic and geometric classifications of complex $3$-dimensional $\delta$-Novikov algebras are given. As a corollary, we prove that there are no simple $3$-dimensional $\delta$-Novikov algebras.

math.RA↗
arXiv2026

The algebraic and geometric classification of derived Jordan and bicommutative algebras

We developed a new proper method for classifying $n$-dimensional derived Jordan algebras, and apply it to the classification of $3$-dimensional derived Jordan algebras. As a byproduct, we have the algebraic classification of $3$-dimensional metabelian commutative algebras and $3$-dimensional derived commutative associative algebras. After that, we introduced a method of classifying $n$-dimensional bicommutative algebras, based on the classification of $n$-dimensional derived commutative associative algebras, and applied it to the classification of $3$-dimensional bicommutative algebras. The second part of the paper is dedicated to the geometric classification of $3$-dimensional metabelian commutative, derived commutative associative, derived Jordan and bicommutative algebras.

math.RA↗
arXiv2025

The algebraic and geometric classification of right alternative and semi-alternative algebras

The algebraic and geometric classifications of complex $3$-dimensional right alternative and semi-alternative algebras are given. As corollaries, we have the algebraic and geometric classification of complex $3$-dimensional $\mathfrak{perm}$, binary $\mathfrak{perm}$, associative, $(-1,1)$-, binary $(-1,1)$-, and assosymmetric algebras. In particular, we proved that the first example of non-associative right alternative algebras appears in dimension $3;$ the first example of non-associative assosymmetric algebras appears in dimension $3;$ the first example of non-assosymmetric semi-alternative algebras appears in dimension $4;$ the first example of binary $(-1,1)$-algebras, which is non-$(-1,1)$-, appears in dimension $4;$ the first example of right alternative algebras, which is not binary $(-1,1)$-, appears in dimension $4;$ the first example of binary $\mathfrak{perm}$ non-$\mathfrak{perm}$ algebras appears in dimension $4.$ As a byproduct, we give a more easy answer to problem 2.109 from the Dniester Notebook, previously resolved by Shestakov and Arenas.

math.RA↗
arXiv2023

Overgroups of exterior powers of an elementary group. Normalizers

We establish two characterizations of an algebraic group scheme $\bigwedge^m GL_n$ over $\mathbb{Z}$. Geometrically, the scheme $\bigwedge^m GL_n$ is a stabilizer of an explicitly given invariant form or, generally, an invariant ideal of forms. Algebraically, $\bigwedge^m GL_n$ is isomorphic (as a scheme over $\mathbb{Z}$) to a normalizer of the elementary subgroup functor $\bigwedge^m E_n$ and a normalizer of the subscheme $\bigwedge^m SL_n$. Our immediate goal is to apply both descriptions in the "sandwich classification" of overgroups of the elementary subgroup. Additionally, the results can be seen as a solution of the linear preserver problem for algebraic group schemes over $\mathbb{Z}$, providing a more functorial description that goes beyond geometry of the classical case over fields.

math.GR↗
arXiv2022

Overgroups of elementary groups in polyvector representations

We initiate the study of subgroups $H$ of the general linear group $GL_{\binom{n}{m}}(R)$ over a commutative ring $R$ that contain the $m$-th exterior power of an elementary group $\bigwedge^mE_n(R)$. Each such group $H$ corresponds to a uniquely defined level $(A_0,\dots,A_{m-1})$, where $A_0,\dots,A_{m-1}$ are ideals of $R$ with certain relations. In the crucial case of the exterior squares, we state the subgroup lattice to be standard. In other words, for $\bigwedge^2E_n(R)$ all intermediate subgroups $H$ are parametrized by a single ideal of the ring $R$. Moreover, we characterize $\bigwedge^mGL_n(R)$ as the stabilizer of a system of invariant forms. This result is classically known for algebraically closed fields, here we prove the corresponding group scheme to be smooth over $\mathbb{Z}$. So the last result holds over arbitrary commutative rings.

math.GR↗
arXiv2022

Overgroups of exterior powers of an elementary group. Levels

We prove a first part of the standard description of groups $H$ lying between an exterior power of an elementary group $\bigwedge^m E_n(R)$ and a general linear group $GL_{n \choose m}(R)$ for a commutative ring $R$, $2\in R^*$ and $n\geqslant 3m$. The description uses the classical notion of a level: for every group $H$ we find a unique ideal $A$ of the ground ring $R$ which describes $H$.

math.GR↗
arXiv2021

The reverse decomposition of unipotents for bivectors

For the second fundamental representation of the general linear group over a commutative ring $R$ we construct straightforward and uniform polynomial expressions of elementary generators as products of elementary conjugates of an arbitrary matrix and its inverse. Towards the solution we get stabilization theorems for any column of a matrix from $GL_{n \choose 2}(R)$ or from the exterior square of $GL_n(R)$, $n\geq 3$.

math.GR↗
arXiv2018

Explicit equations for exterior square of the general linear group

We present several explicit systems of equations defining exterior square of the general linear group as an affine group scheme. Algebraic ingredients of the equations, exterior numbers, are translated into the language of weight diagrams corresponding to Lie groups of type $A_{n-1}$ in representation with the highest weight $\varpi_{2}$.

math.GR↗
arXiv2018

Overgroups of exterior powers of an elementary group. I. Levels and normalizers

In the present paper, we prove the first part in the standard description of groups $H$ lying between $m$-th exterior power of elementary group $E(n,R)$ and the general linear group $GL_{\binom{n}{m}}(R)$. We study structure of the exterior power of elementary group and its relative analog $E\left(\binom{n}{m},R,A\right)$. In the considering case $n \geq 3m$, the description is explained by the classical notion of level: for every such $H$ we find unique ideal $A$ of the ring $R$. Motivated by the problem, we prove the coincidence of the following groups: normalizer of the exterior power of elementary group, normalizer of the exterior power of special linear group, transporter of the exterior power of elementary group into the exterior power of special linear group, and an exterior power of general linear group. This result mainly follows from the found explicit equations for the exterior power of algebraic group scheme $GL_n(\_)$.

math.GR↗