{ "id": "2303.09582", "version": "v1", "published": "2023-03-16T18:02:58.000Z", "updated": "2023-03-16T18:02:58.000Z", "title": "Monomial projections of Veronese varieties: new results and conjectures", "authors": [ "Liena Colarte-Gómez", "Rosa M. Miró-Roig", "Lisa Nicklasson" ], "comment": "To appear in Journal of Algebra", "categories": [ "math.AG", "math.AC" ], "abstract": "In this paper, we consider the homogeneous coordinate rings $A(Y_{n,d}) \\cong \\mathbb{K}[\\Omega_{n,d}]$ of monomial projections $Y_{n,d}$ of Veronese varieties parameterized by subsets $\\Omega_{n,d}$ of monomials of degree $d$ in $n+1$ variables where: (1) $\\Omega_{n,d}$ contains all monomials supported in at most $s$ variables and, (2) $\\Omega_{n,d}$ is a set of monomial invariants of a finite diagonal abelian group $G \\subset GL(n+1,\\mathbb{K})$ of order $d$. Our goal is to study when $\\mathbb{K}[\\Omega_{n,d}]$ is a quadratic algebra and, if so, when $\\mathbb{K}[\\Omega_{n,d}]$ is Koszul or G-quadratic. For the family (1), we prove that $\\mathbb{K}[\\Omega_{n,d}]$ is quadratic when $s \\ge \\lceil \\frac{n+2}{2} \\rceil$. For the family (2), we completely characterize when $\\mathbb{K}[\\Omega_{2,d}]$ is quadratic in terms of the group $G \\subset GL(3,\\mathbb{K})$, and we prove that $\\mathbb{K}[\\Omega_{2,d}]$ is quadratic if and only if it is Koszul. We also provide large families of examples where $\\mathbb{K}[\\Omega_{n,d}]$ is G-quadratic.", "revisions": [ { "version": "v1", "updated": "2023-03-16T18:02:58.000Z" } ], "analyses": { "keywords": [ "veronese varieties", "monomial projections", "conjectures", "finite diagonal abelian group", "quadratic algebra" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }