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Related papers: Toric self-dual Einstein metrics as quotients

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The aim of this thesis is to construct new examples of compact orbifolds $\mathcal{O}^4(\Theta)$ which admit a self dual Einstein (SDE) metric of positive scalar curvature $s>0$, with a one-dimensional group of isometries. In particular we…

Differential Geometry · Mathematics 2007-05-23 Luca Bisconti

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

We describe and construct here pseudo-Hermitian structures $\theta$ without torsion (i.e. with transversal symmetry) whose Webster-Ricci curvature tensor is a constant multiple of the exterior differential $d\theta$. We call these…

Differential Geometry · Mathematics 2007-05-23 Felipe Leitner

We study Einstein deformations of negative K\"ahler Einstein metrics. We relate the second order Einstein deformation theory of negative K\"ahler-Einstein metrics to the complex geometry of the underlying K\"ahler manifold. After suitable…

Differential Geometry · Mathematics 2026-03-11 Paul-Andi Nagy

A theorem of E.Lerman and S.Tolman, generalizing a result of T.Delzant, states that compact symplectic toric orbifolds are classified by their moment polytopes, together with a positive integer label attached to each of their facets. In…

Differential Geometry · Mathematics 2007-05-23 Miguel Abreu

A geometric procedure is elaborated for transforming (pseudo) Riemanian metrics and connections into canonical geometric objects (metric and nonlinear and linear connections) for effective Lagrange, or Finsler, geometries which, in their…

Mathematical Physics · Physics 2012-01-25 Sergiu I. Vacaru

We show that Hermitian-Einstein metrics can be locally constructed by a map from (anti-)self-dual two-forms on Euclidean ${\mathbb R}^4$ to symmetric two-tensors introduced in "Gravitational instantons from gauge theory," H. S. Yang and M.…

High Energy Physics - Theory · Physics 2019-10-02 Kentaro Hara , Akifumi Sako , Hyun Seok Yang

We construct a 2-parameter family of new triaxial $SU(2)$-invariant complete negative Einstein metrics on the complex line bundle $\mathcal{O}(-4)$ over $\mathbb{C}P^1$. The metrics are conformally compact and neither K\"ahler nor…

Differential Geometry · Mathematics 2026-05-01 Qiu Shi Wang

We calculate an upper bound for the second nonzero eigenvalue of the scalar Laplacian, $\lambda_{2}$, for toric K\"ahler-Einstein metrics in terms of the polytope data. We give some detailed examples in complex dimensions 1, 2 and 3. We…

Differential Geometry · Mathematics 2014-02-25 Stuart James Hall , Thomas Murphy

We develop new algorithms for approximating extremal toric K\"ahler metrics. We focus on an extremal metric on $\mathbb{CP}^{2}\sharp2\overline{\mathbb{CP}}^{2}$, which is conformal to an Einstein metric (the Chen-LeBrun-Weber metric). We…

Differential Geometry · Mathematics 2016-01-12 Stuart James Hall , Thomas Murphy

In this article we study the stability problem for positive quaternion-K\"ahler manifolds. We give a description of infinitesimal Einstein deformations and destabilising directions in terms of Laplace eigenfunctions and a special class of…

Differential Geometry · Mathematics 2026-04-03 Yasushi Homma , Uwe Semmelmann

We prove the existence of a Hermitian-Einstein metric on holomorphic vector bundles with a Hermitian metric satisfying the analytic stability condition, under some assumption for the underlying K\"ahler manifolds. We also study the…

Differential Geometry · Mathematics 2019-01-03 Takuro Mochizuki

In this work we study the intrinsic geometry of the space of Kahler metrics under various Riemannian metrics. The first part is on the Dirichlet metric. We motivate its study, we compute its curvature, and we make links with the Calabi…

Differential Geometry · Mathematics 2015-10-20 Simone Calamai , Kai Zheng

The author has elsewhere given a complete classification of those compact oriented Einstein 4-manifolds on which the self-dual Weyl curvature is everywhere positive in the direction of some self-dual harmonic 2-form. In this article,…

Differential Geometry · Mathematics 2019-03-26 Claude LeBrun

The main goal of this thesis is to quantize the Einstein-Hilbert action extended by the quadratic curvature terms within the canonical quantization approach, thus formulating quantum geometrodynamics of the higher derivative theories. The…

General Relativity and Quantum Cosmology · Physics 2020-08-18 Branislav Nikolic

Any oriented $4$-dimensional Einstein metric with semi-definite sectional curvature satisfies the pointwise inequality \[ \frac{|s|}{\sqrt{6}}\geq|W^+|+|W^-|, \] where $s$, $W^+$ and $W^-$ are respectively the scalar curvature, the…

Differential Geometry · Mathematics 2025-03-28 Luca F. Di Cerbo

In the present work some examples of toric hyperkahler metrics in eight dimensions are constructed. First it is described how the Calderbank-Pedersen metrics arise as a consequence of the Joyce description of selfdual structures in four…

High Energy Physics - Theory · Physics 2009-11-10 O. P. Santillan , A. G. Zorin

We consider a class of axially symmetric solutions to Einstein's equations incorporating a $\theta$-dependent scalar field and extend these solutions by introducing electric and magnetic charges via Harrison transformations. Subsequently,…

General Relativity and Quantum Cosmology · Physics 2025-01-23 Mahnaz Tavakoli Kachi , Behrouz Mirza , Fatemeh Sadeghi

In this paper we apply the hyper-K\"ahler quotient construction to Lie groups with a left invariant hyper-K\"ahler structure under the action of a closed abelian subgroup by left multiplication. This is motivated by the fact that some known…

Differential Geometry · Mathematics 2007-05-23 M. L. Barberis , I. Dotti , A. Fino

We consider the problem of finding complete conformal metrics with prescribed curvature functions of the Einstein tensor and of more general modified Schouten tensors. To achieve this, we reveal an algebraic structure of a wide class of…

Differential Geometry · Mathematics 2021-05-04 Rirong Yuan