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Main Author: Delcroix, Thibaut
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2411.07864
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author Delcroix, Thibaut
author_facet Delcroix, Thibaut
contents We prove that, for a spherical Fano threefold not in the Mori-Mukai family 2-29, and a weight function associated with the action of the connected center of a Levi subgroup of its automorphism group, weighted K-polystability is equivalent to vanishing of the weighted Futaki invariant. This is surprising since unlike the case of toric Fano manifold, there exist non-product, special, equivariant test configurations. For the Kähler-Einstein Fano threefold 2-29, and for well-chosen torus action on the three dimensional quadric, we show that this property is false and exhibit explicit examples of weighted optimal degenerations. We then generalize this to higher-dimensional quadrics and blowups of quadrics along a codimension 2 subquadric.
format Preprint
id arxiv_https___arxiv_org_abs_2411_07864
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Weight sensitivity in K-stability of Fano varieties
Delcroix, Thibaut
Algebraic Geometry
Complex Variables
We prove that, for a spherical Fano threefold not in the Mori-Mukai family 2-29, and a weight function associated with the action of the connected center of a Levi subgroup of its automorphism group, weighted K-polystability is equivalent to vanishing of the weighted Futaki invariant. This is surprising since unlike the case of toric Fano manifold, there exist non-product, special, equivariant test configurations. For the Kähler-Einstein Fano threefold 2-29, and for well-chosen torus action on the three dimensional quadric, we show that this property is false and exhibit explicit examples of weighted optimal degenerations. We then generalize this to higher-dimensional quadrics and blowups of quadrics along a codimension 2 subquadric.
title Weight sensitivity in K-stability of Fano varieties
topic Algebraic Geometry
Complex Variables
url https://arxiv.org/abs/2411.07864