Rational components of Hilbert schemes

Paolo Lella; Margherita Roggero

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arXiv · 0903.1029

Rational components of Hilbert schemes

Paolo Lella·Margherita Roggero

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Abstract

The Gr\"obner stratum of a monomial ideal $\id{j}$ is an affine variety that parametrizes the family of all ideals having $\id{j}$ as initial ideal (with respect to a fixed term ordering). The Gr\"obner strata can be equipped in a natural way of a structure of homogeneous variety and are in a close connection with Hilbert schemes of subvarieties in the projective space $\PP^n$. Using properties of the Gr\"obner strata we prove some sufficient conditions for the rationality of components of $\hilb_{p(z)}^n$. We show for instance that all the smooth, irreducible components in $\hilb_{p(z)}^n$ (or in its support) and the Reeves and Stillman component $H_{RS}$ are rational.

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Paolo Lella, Margherita Roggero. 2009-03-05. Rational components of Hilbert schemes. https://arxiv.org/abs/0903.1029

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