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Weighted K–stability and
coercivity with applications to extremal Kähler and Sasaki
metrics
Vestislav Apostolov, Simon Jubert and Abdellah Lahdili |
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Geometry & Topology 27 (2023) 3229–3302
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Abstract |
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We show that a compact weighted extremal Kähler manifold, as defined by the third author (2019), has coercive weighted Mabuchi energy with respect to a maximal complex torus in the reduced group of complex automorphisms. This provides a vast extension and a unification of a number of results concerning Kähler metrics satisfying special curvature conditions, including Kähler metrics with constant scalar curvature, extremal Kähler metrics, Kähler–Ricci solitons, and their weighted extensions. Our result implies the strict positivity of the weighted Donaldson–Futaki invariant of any nonproduct –equivariant smooth Kähler test configuration with reduced central fibre, a property known as –equivariant weighted K–polystability on such test configurations. It also yields the –uniform weighted K–stability on the class of smooth –equivariant polarized test configurations with reduced central fibre. For a class of fibrations constructed from principal torus bundles over a product of Hodge cscK manifolds, we use our results in conjunction with results of Chen and Cheng (2021), He (2019) and Han and Li (2022) in order to characterize the existence of extremal Kähler metrics and Calabi–Yau cones associated to the total space, in terms of the coercivity of the weighted Mabuchi energy of the fibre. This yields a new existence result for Sasaki–Einstein metrics on certain Fano toric fibrations, extending the results of Futaki, Ono and Wang (2009) in the toric Fano case, and of Mabuchi and Nakagawa (2013) in the case of Fano –bundles. |
Keywords
Sasaki and Kähler manifolds, affine cones, special metrics,
weighted K–stability.
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Mathematical Subject Classification
Primary: 32Q20, 53C25, 53C55, 58J60
Secondary: 14J45, 32J27
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References |
Publication
Received: 17 April 2021
Revised: 4 December 2021
Accepted: 6 January 2022
Published: 9 November 2023
Proposed: Gang Tian
Seconded: Frances Kirwan, Simon Donaldson
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Authors |
| Vestislav Apostolov | |
| Département de Mathématiques Université du Québec à Montréal Montréal, QC Canada |
Institute of Mathematics and
Informatics Bulgarian Academy of Sciences Sofia Bulgaria |
| Simon Jubert | |
| Département de Mathématiques Université du Québec à Montréal Montréal, QC Canada |
Institut de Mathématiques de
Toulouse Toulouse France |
| Abdellah Lahdili | |
| Department of Mathematics Aarhus University Aarhus Denmark |
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| © 2023 MSP (Mathematical Sciences Publishers). Distributed under the Creative Commons Attribution License 4.0 (CC BY). |
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