On properness of K-moduli spaces and optimal degenerations of Fano varieties

Abstract We establish an algebraic approach to prove the properness of moduli spaces of K-polystable Fano varieties and reduce the problem to a conjecture on destabilizations of K-unstable Fano varieties. Specifically, we prove that if the stability threshold of every K-unstable Fano...

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Main Authors: Blum, Harold, Halpern-Leistner, Daniel, Liu, Yuchen, Xu, Chenyang
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Springer International Publishing 2021
Online Access:https://hdl.handle.net/1721.1/136911
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author Blum, Harold
Halpern-Leistner, Daniel
Liu, Yuchen
Xu, Chenyang
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Blum, Harold
Halpern-Leistner, Daniel
Liu, Yuchen
Xu, Chenyang
author_sort Blum, Harold
collection MIT
description Abstract We establish an algebraic approach to prove the properness of moduli spaces of K-polystable Fano varieties and reduce the problem to a conjecture on destabilizations of K-unstable Fano varieties. Specifically, we prove that if the stability threshold of every K-unstable Fano variety is computed by a divisorial valuation, then such K-moduli spaces are proper. The argument relies on studying certain optimal destabilizing test configurations and constructing a $$\Theta $$ Θ -stratification on the moduli stack of Fano varieties.
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spelling mit-1721.1/1369112023-12-13T15:38:53Z On properness of K-moduli spaces and optimal degenerations of Fano varieties Blum, Harold Halpern-Leistner, Daniel Liu, Yuchen Xu, Chenyang Massachusetts Institute of Technology. Department of Mathematics Abstract We establish an algebraic approach to prove the properness of moduli spaces of K-polystable Fano varieties and reduce the problem to a conjecture on destabilizations of K-unstable Fano varieties. Specifically, we prove that if the stability threshold of every K-unstable Fano variety is computed by a divisorial valuation, then such K-moduli spaces are proper. The argument relies on studying certain optimal destabilizing test configurations and constructing a $$\Theta $$ Θ -stratification on the moduli stack of Fano varieties. 2021-11-01T14:34:09Z 2021-11-01T14:34:09Z 2021-07-28 2021-07-29T03:19:16Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/136911 Selecta Mathematica. 2021 Jul 28;27(4):73 en https://doi.org/10.1007/s00029-021-00694-7 Creative Commons Attribution-Noncommercial-Share Alike https://creativecommons.org/licenses/by/4.0/ The Author(s), under exclusive licence to Springer Nature Switzerland AG application/pdf Springer International Publishing Springer International Publishing
spellingShingle Blum, Harold
Halpern-Leistner, Daniel
Liu, Yuchen
Xu, Chenyang
On properness of K-moduli spaces and optimal degenerations of Fano varieties
title On properness of K-moduli spaces and optimal degenerations of Fano varieties
title_full On properness of K-moduli spaces and optimal degenerations of Fano varieties
title_fullStr On properness of K-moduli spaces and optimal degenerations of Fano varieties
title_full_unstemmed On properness of K-moduli spaces and optimal degenerations of Fano varieties
title_short On properness of K-moduli spaces and optimal degenerations of Fano varieties
title_sort on properness of k moduli spaces and optimal degenerations of fano varieties
url https://hdl.handle.net/1721.1/136911
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