Limits of graded Gorenstein algebras of Hilbert function (1,3k,1)
2024 (English)In: European Journal of Mathematics, ISSN 2199-675X, E-ISSN 2199-6768, Vol. 10, no 1, article id 9Article in journal (Refereed) Published
Abstract [en]
Let R= k [x, y, z], the polynomial ring over a field k. Several of the authors previously classified nets of ternary conics and their specializations over an algebraically closed field, Abdallah et al. (Eur J Math 9(2), Art. No. 22, 2023). We here show that when k is algebraically closed, and considering the Hilbert function sequence T =(1,3(k),1), k >= 2 (i.e. T = (1, 3, 3, ... , 3, 1) where k is the multiplicity of 3), then the family GT parametrizing graded Artinian algebra quotients A = R/I of R having Hilbert function T is irreducible, and G(T) is the closure of the family Gor(T) of Artinian Gorenstein algebras of Hilbert function T. We then classify up to isomorphism the elements of these families Gor(T) and of G(T). Finally, we give examples of codimension 3 Gorenstein sequences, such as (1, 3, 5, 3, 1), for which G(T) has several irreducible components, one being the Zariski closure of Gor(T).
Place, publisher, year, edition, pages
2024. Vol. 10, no 1, article id 9
Keywords [en]
Artinian Gorenstein algebra, Closure, Deformation, Hilbert function, Irreducible component, Isomorphism class, Limits, Nets of conics, Normal form, Parametrization
National Category
Algebra and Logic
Identifiers
URN: urn:nbn:se:hb:diva-31422DOI: 10.1007/s40879-023-00714-0ISI: 001142227000001Scopus ID: 2-s2.0-85182220162OAI: oai:DiVA.org:hb-31422DiVA, id: diva2:1831008
2024-01-242024-01-242025-09-24Bibliographically approved