{ "id": "2505.10683", "version": "v1", "published": "2025-05-15T19:59:22.000Z", "updated": "2025-05-15T19:59:22.000Z", "title": "$2$-representation infinite algebras from non-abelian subgroups of $\\operatorname{SL}_3$. Part I: Extensions of abelian groups", "authors": [ "Darius Dramburg", "Oleksandra Gasanova" ], "comment": "19 pages. Comments welcome!", "categories": [ "math.RT", "math.RA" ], "abstract": "Let $G \\leq \\operatorname{SL}_3(\\mathbb{C})$ be a non-trivial finite group, acting on $R = \\mathbb{C}[x_1, x_2, x_3]$. The resulting skew-group algebra $R \\ast G$ is $3$-Calabi-Yau, and can sometimes be endowed with the structure of a $3$-preprojective algebra. However, not every such $R \\ast G$ admits such a structure. The finite subgroups of $\\operatorname{SL}_3(\\mathbb{C})$ are classified into types (A) to (L). We consider the groups $G$ of types (C) and (D) and determine for each such group whether the algebra $R \\ast G$ admits a $3$-preprojective structure. We show that the algebra $R \\ast G$ admits a $3$-preprojective structure if and only if $9 \\mid |G|$. Our proof is constructive and yields a description of the involved $2$-representation infinite algebras. This is based on the semi-direct decomposition $G \\simeq N \\rtimes K$ for an abelian group $N$, and we show that the existence of a $3$-preprojective structure on $R \\ast G$ is essentially determined by the existence of one on $R \\ast N$. This provides new classes of $2$-representation infinite algebras, and we discuss some $2$-Auslander-Platzeck-Reiten tilts. Along the way, we give a detailed description of the involved groups and their McKay quivers by iteratively applying skew-group constructions.", "revisions": [ { "version": "v1", "updated": "2025-05-15T19:59:22.000Z" } ], "analyses": { "subjects": [ "16G20", "16S35" ], "keywords": [ "representation infinite algebras", "abelian group", "non-abelian subgroups", "preprojective structure", "extensions" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }