All Questions
3 questions
5
votes
1
answer
193
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Multiple of a flat family of subschemes is flat
Let $X$ be a fixed curve (e.g. a Noetherian, projective scheme of dimension 1, of finite type over an algebraically closed field $k$) and let $S$ be an arbitrary parameter scheme over $k$. Let $D \...
2
votes
0
answers
443
views
Existence of the universal family for the Hilbert scheme of plane curves
Given a finitely generated $k$-algebra $A$ over alg. closed $k$, a family of curves of degree $d$ is defined to be a subscheme $X\subset \mathbb P^2_A$ flat over $A$ whose fibers over closed points of ...
1
vote
0
answers
101
views
Uniqueness of the scheme structure for a given Hilbert polynomial
If we have two lines in $P^3$ which are skewed, then we can take the union of those lines as a subscheme of $P^3$ in order to obtain a subscheme of $P^3$ with a Hilbert Polynomial given by $2m+2$.
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