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Related papers: A note on extremal toric almost K\"ahler metrics

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We introduce a norm on the space of test configurations, which we call the minimum norm. We conjecture that uniform K-stability with respect to this norm is equivalent to the existence of a constant scalar curvature K\"ahler metric. This…

Differential Geometry · Mathematics 2015-06-22 Ruadhaí Dervan

For a closed smooth manifold $M$ admitting a symplectic structure, we define a smooth topological invariant $Z(M)$ using almost-K\"ahler metrics, i.e. Riemannian metrics compatible with symplectic structures. We also introduce $Z(M,…

Differential Geometry · Mathematics 2014-09-19 Jongsu Kim , Chanyoung Sung

In this paper, we study the Abreu equation on toric surfaces. In particular, we prove the existence of the positive extremal metric when relative $K$-stability is assumed.

Differential Geometry · Mathematics 2015-09-24 Bohui Chen , An-Min Li , Li Sheng

We establish a new criterion for a compatible almost complex structure on a symplectic four-manifold to be integrable and hence K\"ahler. Our main theorem shows that the existence of three linearly independent closed J-anti-invariant…

Differential Geometry · Mathematics 2015-09-04 Mehdi Lejmi , Markus Upmeier

Let $(\acute{N},g,\nabla )$\ be a $2n$-dimensional quasi-statistical manifold that admits a pseudo-Riemannian metric $g$ (or $h)$ and a linear connection $\nabla $ with torsion. This paper aims to study an almost Hermitian structure $(g,L)$…

Differential Geometry · Mathematics 2023-07-31 Aydin Gezer , Busra Aktas , Olgun Durmaz

Using spin$^c$ structure we prove that K\"ahler-Einstein metrics with nonpositive scalar curvature are stable (in the direction of changes in conformal structures) as the critical points of the total scalar curvature functional. Moreover if…

Differential Geometry · Mathematics 2007-05-23 Xianzhe Dai , Xiaodong Wang , Guofang Wei

We construct extremal metrics on the total space of certain destabilising test configurations for strictly semistable K\"ahler manifolds. This produces infinitely many new examples of manifolds admitting extremal K\"ahler metrics. It also…

Differential Geometry · Mathematics 2021-10-15 Lars Martin Sektnan , Cristiano Spotti

An almost Abelian group is a non-Abelian Lie group with a codimension 1 Abelian subgroup. This paper investigates invariant Hermitian and K\"{a}hler structures on connected complex almost Abelian groups. We find explicit formulas for the…

Differential Geometry · Mathematics 2023-08-21 Zhirayr Avetisyan , Abigail Brauer , Oderico-Benjamin Buran , Jimmy Morentin , Tianyi Wang

On an almost complex manifold, a quasi-K\"{a}hler metric, with canonical connection in the c-projective class of a given minimal complex connection, is equivalent to a non-degenerate solution of the c-projectively invariant metrizability…

Differential Geometry · Mathematics 2022-01-03 Keegan J. Flood , A. Rod Gover

We show that if a compact K\"ahler manifold admits a weighted extremal metric for the action of a torus, so too does its blowup at a relatively stable point that is fixed by both the torus action and the extremal field. This generalises…

Differential Geometry · Mathematics 2025-05-08 Michael Hallam

Motivated by the torus stability problem, in this work we study K\"ahler metrics with almost non-negative scalar curvature on complex torus. We prove that after passing to a subsequence, non-collapsing sequence of K\"ahler metrics with…

Differential Geometry · Mathematics 2022-04-13 Jianchun Chu , Man-Chun Lee

We introduce a notion of a K\"ahler metric with constant weighted scalar curvature on a compact K\"ahler manifold $X$, depending on a fixed real torus $\mathbb{T}$ in the reduced group of automorphisms of $X$, and two smooth (weight)…

Differential Geometry · Mathematics 2020-01-15 Abdellah Lahdili

In these notes, after an introduction to toric Kahler geometry, we present Calabi's family of U(n)-invariant extremal Kahler metrics in symplectic action-angle coordinates and show that it actually contains, as particular cases, many…

Differential Geometry · Mathematics 2009-12-03 Miguel Abreu

This paper concerns the explicit construction of extremal Kaehler metrics on total spaces of projective bundles, which have been studied in many places. We present a unified approach, motivated by the theory of hamiltonian 2-forms (as…

Differential Geometry · Mathematics 2015-06-26 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon , Christina W. Tonnesen-Friedman

This paper is concerned with the existence of metrics of constant Hermitian scalar curvature on almost-K\"ahler manifolds obtained as smoothings of a constant scalar curvature K\"ahler orbifold, with $A_1$ singularities. More precisely,…

Differential Geometry · Mathematics 2018-06-21 Caroline Vernier

In this note, we prove that on polarized toric manifolds the relative $K$-stability with respect to Donaldson's toric degenerations is a necessary condition for the existence of Calabi's extremal metrics, and also we show that the modified…

Differential Geometry · Mathematics 2007-06-05 Bin Zhou , Xiaohua Zhu

We study the existence of weighted extremal K\"ahler metrics in the sense of Apostolov-Calderbank-Gauduchon-Legendre and Lahdili on the total space of an admissible projective bundle over a Hodge K\"ahler manifold of constant scalar…

Differential Geometry · Mathematics 2018-08-09 Vestislav Apostolov , Gideon Maschler , Christina W. Tønnesen-Friedman

We establish a regularity result for the metric on any 4-dimensional extremal K\"ahler manifold, and a weak compactness theorem on the space of such metrics. Specifically, the sectional curvature at a point is bounded when the quantity…

Differential Geometry · Mathematics 2011-05-11 Brian Weber

We present a local classification of conformally equivalent but oppositely oriented 4-dimensional Kaehler metrics which are toric with respect to a common 2-torus action. In the generic case, these "ambitoric" structures have an intriguing…

Differential Geometry · Mathematics 2016-11-28 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon

We give an explicit local classification of conformally equivalent but oppositely oriented Kaehler metrics on a 4-manifold which are toric with respect to a common 2-torus action. In the generic case, these structures have an intriguing…

Differential Geometry · Mathematics 2013-03-01 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon