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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,695 papers · 148 categories

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61121182242 · Jun 202019922001200920172026
48 results for Extremal metrics

The study finds no extremal metrics for eigenvalues on compact manifolds but constructs examples for annuli.

problem Finding extremal metrics for eigenvalues on compact manifolds.
method Construction of conformally extremal metrics in annuli and analysis of non-existence.
result Construction of conformally extremal metrics in annuli and characterization of these metrics.

New Kähler metrics generalize Calabi's and relate to Fano manifolds.

problem Existence of extremal Kähler metrics on Fano manifolds.
method Introducing σσ-extremal Kähler metrics and relating them to multiplier Hermitian-Einstein metrics.
result Existence of σσ-extremal Kähler metrics implies existence of multiplier Hermitian-Einstein metrics on Fano manifolds.

Uniqueness of weighted extremal metrics on Kähler manifolds proven.

problem Uniqueness of weighted extremal Kähler metrics on compact Kähler manifolds.
method Proof of uniqueness using modified Mabuchi energy and weighted K-semistability.
result Uniqueness of weighted extremal Kähler metrics up to automorphisms.

The paper classifies rotationally symmetric extremal Kähler metrics on complex manifolds.

problem Classifying extremal Kähler metrics on complex manifolds.
method Analyzing polynomial zeros in Calabi's extremal equation.
result No U(n)U(n) invariant complete extremal Kähler metrics on Cn\mathbb C^n with positive bisectional curvature.

We provide a new proof of a result of X.X.Chen and G.Tian : for a polarized extremal Kähler manifold, an extremal metric attains the minimum of the modified K-energy. The proof uses an idea of C.Li adapted to the extremal metrics using some weighted balanced metrics.

2012-11-23abs ↗pdf ↗

New toric Fano manifolds found without extremal Kähler metrics.

problem Finding toric Fano manifolds without extremal Kähler metrics.
method Constructing specific toric Fano manifolds of dimensions 10 and n (n≥11) that do not admit extremal Kähler metrics.
result Existence of toric Fano manifolds of dimension 10 and higher that do not admit extremal Kähler metrics.

This paper is a survey of some recent progress on the study of Calabi's extremal Kähler metrics. We first discuss the Yau-Tian-Donaldson conjecture relating the existence of extremal metrics to an algebro-geometric stability notion and we give some example settings where this conjecture has been established. We then tu…

2014-05-19abs ↗pdf ↗

Three distinct 3D components found in local extremal Kähler metrics.

problem Characterizing extremal Kähler metrics in one dimension.
method Defined local extremal Kähler metrics and analyzed their germs.
result Space of germs of local extremal Kähler metrics in one dimension comprises three distinct R3{\Bbb R}^3 components.

We study algebro-geometric consequences of the quantised extremal Kähler metrics, introduced in the previous work of the author. We prove that the existence of quantised extremal metrics implies weak relative Chow polystability. As a consequence, we obtain asymptotic weak relative Chow polystability and KK-semistabili…

2017-05-31abs ↗pdf ↗

In this paper, we consider a compact Kahler manifold with extremal Kahler metric and a Mumford stable holomorphic bundle over it. We proved that, if the holomorphic vector field defining the extremal Kahler metric is liftable to the bundle and if the bundle is relatively stable with respect to the action of automorphis…

2013-10-11abs ↗pdf ↗

Bi-invariant metrics on Lie groups and homogeneous spaces are extremal and rigid.

problem Gromov's question on extremality of bi-invariant metrics on compact Lie groups.
method Proving rigidity of bi-invariant metrics on compact Lie groups and homogeneous spaces.
result Bi-invariant metrics on compact Lie groups and homogeneous spaces are extremal and rigid.

In this paper we extend recent breakthrough of Chen-Cheng \cite{CC1, CC2, CC3} on existence of constant scalar Kähler metric on a compact Kähler manifold to Calabi's extremal metric. Our argument follows \cite{CC3} and there are no new a prior estimates needed, but rather there are necessary modifications adapted to th…

2018-01-23abs ↗pdf ↗

El Soufi-Ilias' theorem establishes a connection between minimal submanifolds of spheres and extremal metrics for eigenvalues of the Laplace-Beltrami operator. Recently, this connection was used to provide several explicit examples of extremal metrics. We investigate the maximality of these metrics and prove that all o…

2012-10-30abs ↗pdf ↗

We consider the stability of Sasaki-extremal metrics under deformations of the complex structure on the Reeb foliation. Given such a deformation preserving the action of a compact subgroup of the automorphism group of a Sasaki-extremal structure, a sufficient condition is given involving the nondegeneracy of the relati…

2012-04-07abs ↗pdf ↗

Consider a compact Kähler manifold X with a simple normal crossing divisor D, and define Poincaré type metrics on X\D as Kähler metrics on X\D with cusp singularities along D. We prove that the existence of a constant scalar curvature (resp. an extremal) Poincaré type Kähler metric on X\D implies the existence of a con…

2013-12-31abs ↗pdf ↗

Study classifies special metrics on specific surfaces.

problem Classifying extremal Kähler metrics with singularities.
method Analyzes Hessian of the Curvature of the Metric on K-surfaces.
result Identifies non-CSC HCMU metrics on S{α}2S^2_{\{α\}} and S{α,β}2S^2_{\{α,β\}}.

Based on recent work of S. K. Donaldson and T. Mabuchi, we prove that any extremal Kaehler metric in the sense of E. Calabi, defined on the product of polarized compact complex projective manifolds is the product of extremal Kaehler metrics on each factor, provided that the integral Futaki invariants of the polarized m…

2012-12-15abs ↗pdf ↗

Sharp inequalities and extremizers for J functional on Kähler manifolds.

problem Understanding the large scale asymptotic of the J functional on Kähler metrics.
method Proving sharpness of inequalities and studying extremizing potentials/rays on toric Kähler manifolds, and existence of radial extremizers on general Kähler manifolds.
result Sharpness of inequalities and existence of extremizing potentials/rays on toric Kähler manifolds, and equivalence with plurisupported currents on general Kähler manifolds.

We apply recently developed convex programs to find the minimal-area Riemannian metric on 2n2n-sided polygons (n3n\geq 3) with length conditions on curves joining opposite sides. We argue that the Riemannian extremal metric coincides with the conformal extremal metric on the regular 2n2n-gon. The hexagon was considered…

2019-03-28abs ↗pdf ↗

Consider a fibred compact Kähler manifold X endowed with a relatively ample line bundle, such that each fibre admits a constant scalar curvature Kähler metric and has discrete automorphism group. Assuming the base of the fibration admits a twisted extremal metric where the twisting form is a certain Weil-Petersson type…

2017-12-14abs ↗pdf ↗

The paper explores existence and non-existence of constant scalar curvature and extremal Sasaki metrics.

problem Existence and non-existence of constant scalar curvature and extremal Sasaki metrics.
method Analyzing natural Sasaki-Boothby-Wang manifolds and extremal Sasaki metrics on admissible projective bundles.
result The extremal Sasaki--Reeb cone is not necessarily connected and can be empty even in the non-Gorenstein case.

We give conditions under which the blowup of an extremal Kähler manifold along a submanifold of codimension greater than two admits an extremal metric. This generalizes work of Arezzo-Pacard-Singer, who considered blowups in points.

2016-10-21abs ↗pdf ↗

The first eigenvalue of the Laplacian on a surface can be viewed as a functional on the space of Riemannian metrics of a given area. Critical points of this functional are called extremal metrics. The only known extremal metrics are a round sphere, a standard projective plane, a Clifford torus and an equilateral torus.…

2003-11-26abs ↗pdf ↗

Let (X,L) be a polarized Kähler manifold that admits an extremal Kähler metric in c1(L). We show that on a nearby polarized deformation that preserves the symmetry induced by the extremal vector field of (X,L), the modified K-energy is bounded from below. This generalizes a result of Chen, Székelyhidi and Tosatti to ex…

2013-02-04abs ↗pdf ↗

The paper proves the existence of a special Kähler metric on a minimal ruled surface.

problem Existence of higher extremal Kähler metrics on a minimal ruled surface.
method Proved the existence of a higher extremal Kähler metric by showing it satisfies a specific equation and computed the top Bando-Futaki invariant.
result Higher extremal Kähler metrics exist on a minimal ruled surface, but not higher constant scalar curvature Kähler metrics.