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Related papers: Hilbert schemes with two Borel-fixed points

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We extend the recent classification of Hilbert schemes with two Borel-fixed points to arbitrary characteristic. We accomplish this by synthesizing Reeves' algorithm for generating strongly stable ideals with the basic properties of…

Algebraic Geometry · Mathematics 2021-08-03 Andrew P. Staal

We investigate the geography of Hilbert schemes parametrizing closed subschemes of projective space with specified Hilbert polynomials. We classify Hilbert schemes with unique Borel-fixed points via combinatorial expressions for their…

Algebraic Geometry · Mathematics 2020-07-28 Andrew P. Staal

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

We develop a new general method for computing the decomposition type of the normal bundle to a projective rational curve. This method is then used to detect and explain an example of a Hilbert scheme that parametrizes all the rational…

Algebraic Geometry · Mathematics 2016-04-21 Alberto Alzati , Riccardo Re

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

Borel-fixed ideals play a key role in the study of Hilbert schemes. Indeed each component and each intersection of components of a Hilbert scheme contains at least one Borel-fixed point, i.e. a point corresponding to a subscheme defined by…

Symbolic Computation · Computer Science 2012-05-03 Paolo Lella

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

In this paper we determine the irreducible components of the Hilbert schemes H(4,g) of locally Cohen-Macaulay space curves of degree four and arbitrary arithmetic genus g. We show that these Hilbert schemes are connected, in spite of having…

Algebraic Geometry · Mathematics 2010-03-26 Scott Nollet , Enrico Schlesinger

The multigraded Hilbert scheme parametrizes all homogeneous ideals in a polynomial ring graded by an abelian group with a fixed Hilbert function. We prove that any multigraded Hilbert scheme is smooth and irreducible when the polynomial…

Algebraic Geometry · Mathematics 2010-03-15 Diane Maclagan , Gregory G. Smith

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 investigate the Hilbert scheme of points on a smooth threefold. We introduce a notion of broken Gorenstein structure for finite schemes, and show that its existence guarantees smoothness on the Hilbert scheme. Moreover, we conjecture…

Algebraic Geometry · Mathematics 2026-05-05 Joachim Jelisiejew , Ritvik Ramkumar , Alessio Sammartano

In this article, we describe the irreducible components of the Hilbert scheme of $d$ points on $\mathbb{A}^n$ for $d=9,10$. The main techniques we use are the variety of commuting matrices and analyzing loci of local algebras with a…

Algebraic Geometry · Mathematics 2025-12-11 Maciej Gałązka , Hanieh Keneshlou , Klemen Šivic

We study the component structures of some standard-graded Hilbert schemes closely related to a Hilbert scheme of curves studied by Gotzmann. In particular, we encounter examples of singular lex-segment points lying on two and three…

Algebraic Geometry · Mathematics 2021-03-05 Andrew P. Staal

In this PhD thesis we propose an algorithmic approach to the study of the Hilbert scheme. Developing algorithmic methods, we also obtain general results about Hilbert schemes. In Chapter 1 we discuss the equations defining the Hilbert…

Algebraic Geometry · Mathematics 2012-02-21 Paolo Lella

This paper presents new examples of elementary and non-elementary irreducible components of the Hilbert scheme of points and its nested variants. The results are achieved via a careful analysis of the deformations of a class of finite…

Algebraic Geometry · Mathematics 2025-07-04 Franco Giovenzana , Luca Giovenzana , Michele Graffeo , Paolo Lella

We investigate some aspects of the geometry of two classical generalisations of the Hilbert schemes of points. Precisely, we show that parity conjecture for $\text{Quot}_r^d\mathbb{A}^3$ already fails for $d=8$ and $r=2$ and that lots of…

Algebraic Geometry · Mathematics 2024-06-24 Franco Giovenzana , Luca Giovenzana , Michele Graffeo , Paolo Lella

Let $\mathcal{I}_{d,g,r}$ be the union of irreducible components of the Hilbert scheme whose general points correspond to smooth irreducible non-degenerate curves of degree $d$ and genus $g$ in $\mathbb{P}^r$. We use families of curves on…

Algebraic Geometry · Mathematics 2020-03-17 Youngook Choi , Hristo Iliev , Seonja Kim

We study the geometry of standard graded Hilbert schemes of polynomial rings and exterior algebras. Our investigation is motivated by a famous theorem of Reeves and Stillman for the Grothendieck Hilbert scheme, which states that the…

Algebraic Geometry · Mathematics 2023-02-08 Ritvik Ramkumar , Alessio Sammartano

In this paper we introduce an effective method to construct rational deformations between couples of Borel-fixed ideals. These deformations are governed by flat families, so that they correspond to rational curves on the Hilbert scheme.…

Commutative Algebra · Mathematics 2010-10-27 Paolo Lella

Following the approach in the book "Commutative Algebra", by D. Eisenbud, where the author describes the generic initial ideal by means of a suitable total order on the terms of an exterior power, we introduce first the generic initial…

Algebraic Geometry · Mathematics 2016-11-22 Cristina Bertone , Francesca Cioffi , Margherita Roggero
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