Saved in:
Bibliographic Details
Main Authors: Hallam, Michael, Lahdili, Abdellah
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2408.06267
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910563733340160
author Hallam, Michael
Lahdili, Abdellah
author_facet Hallam, Michael
Lahdili, Abdellah
contents We introduce a new weighted version of the Hermite--Einstein equation, along with notions of weighted slope (semi/poly)stability, and prove that a vector bundle admits a weighted Hermite--Einstein metric if and only if it is weighted slope polystable. The new equation encompasses several well-known examples of canonical Hermitian metrics on vector bundles, including the usual Hermite--Einstein metrics, Kähler--Ricci solitons, and transversally Hermite--Einstein metrics on certain Sasaki manifolds. We prove that the equation arises naturally as a moment map, that solutions to the equation are unique up to scaling, and demonstrate a weighted Kobayashi--Lübke inequality satisfied by vector bundles admitting a weighted Hermite--Einstein metric. As an application of our techniques, we extend a bound of Tian on the Ricci curvature to a bound on a modified Ricci curvature, related to the existence of Kähler--Ricci solitons. Along the way, we introduce a new weighted vortex equation, as well as a weighted analogue of Gieseker stability. A key technical point is the application of a new extension of Inoue's equivariant intersection numbers to arbitrary weight functions on the moment polytope of a Kähler manifold with Hamiltonian torus action.
format Preprint
id arxiv_https___arxiv_org_abs_2408_06267
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The weighted Hermite--Einstein equation
Hallam, Michael
Lahdili, Abdellah
Differential Geometry
Algebraic Geometry
53C07, 32L05
We introduce a new weighted version of the Hermite--Einstein equation, along with notions of weighted slope (semi/poly)stability, and prove that a vector bundle admits a weighted Hermite--Einstein metric if and only if it is weighted slope polystable. The new equation encompasses several well-known examples of canonical Hermitian metrics on vector bundles, including the usual Hermite--Einstein metrics, Kähler--Ricci solitons, and transversally Hermite--Einstein metrics on certain Sasaki manifolds. We prove that the equation arises naturally as a moment map, that solutions to the equation are unique up to scaling, and demonstrate a weighted Kobayashi--Lübke inequality satisfied by vector bundles admitting a weighted Hermite--Einstein metric. As an application of our techniques, we extend a bound of Tian on the Ricci curvature to a bound on a modified Ricci curvature, related to the existence of Kähler--Ricci solitons. Along the way, we introduce a new weighted vortex equation, as well as a weighted analogue of Gieseker stability. A key technical point is the application of a new extension of Inoue's equivariant intersection numbers to arbitrary weight functions on the moment polytope of a Kähler manifold with Hamiltonian torus action.
title The weighted Hermite--Einstein equation
topic Differential Geometry
Algebraic Geometry
53C07, 32L05
url https://arxiv.org/abs/2408.06267