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Related papers: Pathologies on the Hilbert scheme of points

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We use generalised Bialynicki-Birula decomposition, apolarity and obstruction theories to prove non-reducedness of the Hilbert scheme of $13$ points on $\mathbb{A}^6$. Our argument doesn't involve computer calculations and gives an example…

Algebraic Geometry · Mathematics 2021-09-27 Michał Szachniewicz

We generalize the Bialynicki-Birula decomposition to singular schemes and apply it to the Hilbert scheme of points on an affine space. We find an infinite family of small, elementary and generically smooth components of the Hilbert scheme…

Algebraic Geometry · Mathematics 2019-04-09 Joachim Jelisiejew

An open question is whether the Hilbert scheme of points of a high dimensional affine space satisfies Murphy's Law, as formulated by Vakil. In this short note, we instead consider the loci in the Hilbert scheme parametrizing punctual…

Algebraic Geometry · Mathematics 2018-04-30 Daniel Erman

The criterion for an affine primary algebra over the field to be integral, is proven. Using this criterion we give a simple proof that Hilbert scheme of 0-dimensional subschemes of length $l$ of nonsingular $d$-dimensional algebraic variety…

Algebraic Geometry · Mathematics 2015-04-29 Nadezda Timofeeva

We give a short, elementary and explicit proof of the existence of Hilbert schemes of points on affine schemes. As a direct consequence we obtain the existence of the Hilbert scheme of points on any projective scheme, not necessarily of…

Algebraic Geometry · Mathematics 2007-05-23 Trond Gustavsen , Dan Laksov , Roy Skjelnes

We prove that the Hilbert scheme of points on a normal quasi-projective surface with at worst rational double point singularities is irreducible.

Algebraic Geometry · Mathematics 2017-01-11 Xudong Zheng

Let H_{ab} be the equivariant Hilbert scheme parametrizing the 0-dimensional subschemes of the affine plane invariant under the natural action of the one-dimensional torus T_{ab}:={(t^{-b},t^a), t\in k^*}. We compute the irreducible…

Algebraic Geometry · Mathematics 2007-05-23 Laurent Evain

We give a linear algebraic and a monadic descriptions of the Hilbert scheme of points on the affine space of dimension $n$ which naturally extends Nakajima's representation of the Hilbert scheme of points on the plane. As an application of…

Algebraic Geometry · Mathematics 2018-11-28 Abdelmoubine Amar Henni , Marcos Jardim

We exhibit generically nonreduced components of the Hilbert scheme of at least $21$ points on a smooth variety of dimension at least four. The result was announced in~[Jelisiejew__open_problems] and answers a question~[Problem~3.8, AIMPL].…

Algebraic Geometry · Mathematics 2024-07-01 Joachim Jelisiejew

We classify the irreducible components of the Hilbert scheme of $n$ points on non-reduced algebraic plane curves, and give a formula for the multiplicities of the irreducible components. The irreducible components are indexed by partitions…

Algebraic Geometry · Mathematics 2023-10-24 Yuze Luan

We investigate the Hilbert scheme of points on curves with n-fold singularities, that is curves that look locally around their singular points as the axis in an affine space. We describe the structure and number of its irreducible…

Algebraic Geometry · Mathematics 2025-11-06 Ángel David Ríos Ortiz , Javier Sendra-Arranz

We prove that the Gorenstein locus of the Hilbert scheme of points on $\mathbb A^n$ is non-reduced for $n\geq 12$; we construct examples of non-reduced points that come from apolar algebras of the sum of general cubics. As a corollary, we…

Algebraic Geometry · Mathematics 2026-02-12 Piotr Oszer

We construct irrational irreducible components of the Hilbert scheme of points of affine n-dimensional space, for n at least 12. We start with irrational components of the Hilbert scheme of curves in P^3 and use methods developed by…

Algebraic Geometry · Mathematics 2024-06-03 Gavril Farkas , Rahul Pandharipande , Alessio Sammartano

We prove that the Hilbert scheme of 11 points on a smooth threefold is irreducible. In the course of the proof, we present several known and new techniques for producing curves on the Hilbert scheme.

Algebraic Geometry · Mathematics 2017-01-12 Theodosios Douvropoulos , Joachim Jelisiejew , Bernt Ivar Utstøl Nødland , Zach Teitler

The Hilbert scheme of $n$ points in the affine plane contains the open subscheme parametrizing $n$ distinct points in the affine plane, and the closed subscheme parametrizing ideals of codimension $n$ supported at the origin of the affine…

Algebraic Geometry · Mathematics 2014-07-03 Mathias Lederer

The diagonal in a product of projective spaces is cut out by the ideal of 2x2-minors of a matrix of unknowns. The multigraded Hilbert scheme which classifies its degenerations has a unique Borel-fixed ideal. This Hilbert scheme is generally…

Algebraic Geometry · Mathematics 2009-08-27 Dustin Cartwright , Bernd Sturmfels

We characterize Hilbert polynomials that give rise to Hilbert schemes with two Borel-fixed points and determine when the associated Hilbert schemes or their irreducible components are smooth. In particular, we show that the Hilbert scheme…

Algebraic Geometry · Mathematics 2022-11-15 Ritvik Ramkumar

We sharpen and generalize the dimension growth bounds for the number of points of bounded height lying on an irreducible algebraic variety of degree $d$, over any global field. In particular, we focus on the affine hypersurface situation by…

Number Theory · Mathematics 2025-12-05 Raf Cluckers , Pierre Dèbes , Yotam I. Hendel , Kien Huu Nguyen , Floris Vermeulen

We construct a stratification of the punctual Hilbert scheme of points on a non-reduced and nodal plane curve, $x^uy^v=0$. Each stratum is indexed by a new combinatorial object we define: a weak diagonal partition. The approach is based on…

Algebraic Geometry · Mathematics 2026-04-07 Yuze Luan

We study the geometry and topology of Hilbert schemes of points on the orbifold surface [C^2/G], respectively the singular quotient surface C^2/G, where G is a finite subgroup of SL(2,C) of type A or D. We give a decomposition of the…

Algebraic Geometry · Mathematics 2018-02-02 Ádám Gyenge , András Némethi , Balázs Szendrői
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