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Finding a cover of the Hilbert functor, that corresponds to a cover of the Grassmannian

Let $\mathrm{Grass}_{k+1,n+1}:\mathrm{Sch}^{\circ}\rightarrow\mathrm{Set}$ be the Grassmann functor, which maps a scheme $S$ to the set: $$\left\{\mathscr{U}\subseteq\mathscr{O}_S^{n+1}:\,\,\mathscr{...
BenediktK's user avatar
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2 votes
0 answers
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A Subfunctor of Quot-functor compatible with pullbacks

Let $X$ be a smooth projective irreducible algebraic curve over field $k$. For $d,r,k,m >0$ the representable Quot scheme $\mathcal {Quot}_X^{r,d}(\mathcal{O}_X(m)^k)$ is given for any test scheme $...
user267839's user avatar
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2 votes
0 answers
249 views

Smoothness of Hilbert scheme of rational normal curves

I'm trying to solve Exercise 1.26 from the book "Moduli of Curves" by Harris and Morrison on page 14: Exercise (1.26) Determine the normal bundle to the rational normal curve $C \subset \...
user267839's user avatar
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2 votes
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representability of some mapping stack

Let $S$ be an Artin stack of finite type. We assume that it contains a point as an open dense. Is it always true that the mapping stack: $Hom^{0}(\mathbb{P}^{1},S)$ which consists of sections ...
prochet's user avatar
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1 vote
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108 views

L.c.i locus of Hilbert scheme of points on singular varieties

Let $X$ be an algebraic variety over $\mathbb{C}$. What can we say about the l.c.i. locus of $\text{Hilb}^n(X)$? When $X$ is smooth, it is well-known that the l.c.i. locus of $\text{Hilb}^n(X)$ is ...
Chan Ki Fung's user avatar
1 vote
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84 views

Relation between quot scheme of birational curve

I am very new to algebraic geometry. Currently reading about Hilbert and quot scheme. I want to know more about the structure and properties of Hilbert and quot schemes over curves. My question is the ...
KAK's user avatar
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1 vote
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Symmetric 0-dimensional schemes with generic Hilbert function and Grassmannians

I've came across this problem while thinking about some properties of fat schemes. Let me give you an explicit (motivating) example: We have $S=\mathbb{C}[x,y,z]$, the coordinate ring of $\mathbb{P}^2$...
gigi's user avatar
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1 vote
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169 views

Étaleness of Isom scheme $\operatorname{Isom}_S(X,Y)$

Let $S$ be a quasi-projective scheme over base field $k$ and $X, Y$ two finite étale schemes over $S$ and assume we are in situation we know that the isom space $\operatorname{Isom}_S(X,Y)$ exists as ...
user267839's user avatar
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1 vote
0 answers
324 views

On construction of Hilbert and Quot schemes

I have some questions regarding the strategy of the proof of the existence of Hilbert and Quot schemes (I will focus on the latter since it's more general), as in the book Fundamental Algebraic ...
Lao-tzu's user avatar
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Use of flattening stratification (from Nitsure's construction of Hilbert and Quot schemes)

I study Nitin Nitsures paper on the Construction of Hilbert and Quot Schemes and not understand the propetry (F) completely: In previous chapter (Embedding Quot into Grassmanian) it was proved that ...
user267839's user avatar
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403 views

hypersurface of degree d Hilbert polynomial

I am in trouble to solve part (2) Exercise 1.13 from "Moduli of Curves" by Harris and Morrison on page 9: Exercise (1.13) 2) Fix a subscheme $X \subset \mathbb{P}^r$. Show, by taking ...
user267839's user avatar
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