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In this note we give a characterization of Kaehler metrics which are both Calabi extremal and Kaehler-Ricci solitons in terms of complex Hessians and the Riemann curvature tensor. We apply it to prove that, under the assumption of…

Differential Geometry · Mathematics 2015-12-11 Simone Calamai , David Petrecca

In this work, we apply the anholonomic deformation method for constructing new classes of anisotropic cosmological solutions in Einstein gravity and/or generalizations with nonholonomic variables. There are analyzed four types of, in…

Mathematical Physics · Physics 2015-05-18 Sergiu I. Vacaru

We show that solutions of the Seiberg-Witten equations lead to non-trivial lower bounds for the L2-norm of the Weyl curvature of a compact Riemannian 4-manifold. These estimates are then used to derive new obstructions to the existence of…

Differential Geometry · Mathematics 2007-05-23 Claude LeBrun

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

This paper investigates the question of which smooth compact 4-manifolds admit Riemannian metrics that minimize the L2-norm of the curvature tensor. Metrics with this property are called OPTIMAL; Einstein metrics and scalar-flat…

Differential Geometry · Mathematics 2007-05-23 Claude LeBrun

This paper presents a systematic study of invariant Einstein metrics on basic classical Lie supergroups, whose Lie superalgebras belong to the Kac's classification of finite dimensional classical simple Lie superalgebras over $\mathbb{R}$.…

Differential Geometry · Mathematics 2025-08-29 Huihui An , Zaili Yan , Shaoxiang Zhang

We investigate four-dimensional Heterotic solitons, defined as a particular class of solutions of the equations of motion of Heterotic supergravity on a four-manifold $M$. Heterotic solitons depend on a parameter $\kappa$ and consist of a…

Differential Geometry · Mathematics 2024-12-25 Andrei Moroianu , Ángel Murcia , C. S. Shahbazi

This is a collection of notes on the properties of left-invariant metrics on the eight-dimensional compact Lie group SU(3). Among other topics we investigate the existence of invariant pseudo-Riemannian Einstein metrics on this manifold. We…

Differential Geometry · Mathematics 2021-07-27 Robert Coquereaux

As seen in the works of Calabi, Cheng-Yau and Loftin, affine sphere equations have a close relationship with Kaehler-Einstein metrics. The main purpose of this note is to show that an equation analogous to those of hyperbolic affine spheres…

Differential Geometry · Mathematics 2007-10-02 Toshiki Mabuchi

We find a new obstruction for a real Einstein 4-orbifold with an A1-singularity to be a limit of smooth Einstein 4-manifolds. The obstruction is a curvature condition at the singular point. For asymptotically hyperbolic metrics, with…

Differential Geometry · Mathematics 2011-05-26 Olivier Biquard

We study locally conformal calibrated $G_2$-structures whose underlying Riemannian metric is Einstein, showing that in the compact case the scalar curvature cannot be positive. As a consequence, a compact homogeneous $7$-manifold cannot…

Differential Geometry · Mathematics 2020-08-11 Anna Fino , Alberto Raffero

Given any two Einstein (pseudo-)metrics, with scalar curvatures suitably related, we give an explicit construction of a Poincar\'e-Einstein (pseudo-)metric with conformal infinity the conformal class of the product of the initial metrics.…

Differential Geometry · Mathematics 2009-11-16 A. Rod Gover , Felipe Leitner

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

A construction of Kaehler-Einstein metrics using Galois coverings, studied by Arezzo-Ghigi-Pirola, is generalized to orbifolds. By applying it to certain orbifold covers of P^n which are trivial set theoretically, one obtains new Einstein…

Differential Geometry · Mathematics 2007-05-23 Alessandro Ghigi , János Kollár

The aim of the present work is twofold: first, we show how all the $n$-dimensional Riemannian and Lorentzian metrics can be constructed from a certain class of systems of second-order PDE's which are in duality to the Hamilton-Jacobi…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Emanuel Gallo , Magdalena Marciano-Melchor , Gilberto Silva-Ortigoza

Recently Guillemin gave an explicit combinatorial way of constructing "toric" Kahler metrics on (symplectic) toric varieties, using only data on the moment polytope. In this paper, differential geometric properties of these metrics are…

dg-ga · Mathematics 2007-05-23 Miguel Abreu

In earlier work we have shown that for certain geometric structures on a smooth manifold $M$ of dimension $n$, one obtains an almost para-K\"ahler--Einstein metric on a manifold $A$ of dimension $2n$ associated to the structure on $M$. The…

Differential Geometry · Mathematics 2024-09-17 Andreas Cap , Thomas Mettler

We construct a new class of stationary exact solutions to five-dimensional Einstein-Gauss-Bonnet gravity. The solutions are based on four-dimensional self-dual Atiyah-Hitchin geometry. We find analytical solutions to the five-dimensional…

High Energy Physics - Theory · Physics 2019-07-22 Michael Butler , Masoud Ghezelbash , Erfan Massaeli , Maysam Motaharfar

Many papers on modified gravity theories (MGTs), and metric-affine geometry have been published. New classes of black hole (BH), wormhole (WH), and cosmological solutions involving nonmetricity and torsion fields were constructed.…

General Physics · Physics 2025-06-13 Sergiu I. Vacaru

We study Einstein metrics on smooth compact 4-manifolds with an edge-cone singularity of specified cone angle along an embedded 2-manifold. To do so, we first derive modified versions of the Gauss-Bonnet and signature theorems for arbitrary…

Differential Geometry · Mathematics 2017-05-17 Michael Atiyah , Claude LeBrun