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We prove that there are no restrictions on the spatial topology of asymptotically flat solutions of the vacuum Einstein equations in (n+1)-dimensions. We do this by gluing a solution of the vacuum constraint equations on an arbitrary…

General Relativity and Quantum Cosmology · Physics 2016-11-23 James Isenberg , Rafe Mazzeo , Daniel Pollack

We prove the linear stability with respect to the Einstein-Hilbert action of the symmetric spaces $\mathrm{SU}(n)$, $n\geq3$, and $E_6/F_4$. Combined with earlier results, this resolves the stability problem for irreducible symmetric spaces…

Differential Geometry · Mathematics 2021-10-08 Paul Schwahn

We investigate five dimensional Einstein spaces in warped geometries from the point of view of the four dimensional physically relevant Robertson-Walker-Friedman cosmological metric and the Schwarzschild metric. We show that a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 M. Arik , A. Baykal , M. C. Çalik , D. Çiftci , Ö. Delice

We study null Sasakian structures in dimension five. First, based on a result due to Koll\'ar [Ko], we improve a result by Boyer, Galicki and Matzeu in [BGM] and prove that simply connected manifolds diffeomorphic to $# k(S^2\times S^3)$…

Differential Geometry · Mathematics 2024-03-04 Jaime Cuadros

A proof of the isometric embedding of a given two-metric in E^3 of class C^1. The method uses the theory of first order partial differential equations. The curvature of the metric plays no role in the proof.

Differential Geometry · Mathematics 2017-12-19 Edgar Kann

The projective curvature tensor $P$ is invariant under a geodesic preserving transformation on a semi-Riemannian manifold. It is well known that $P$ is not a generalized curvature tensor and hence it possesses different geometric properties…

Differential Geometry · Mathematics 2016-09-16 Absos Ali Shaikh , Haradhan Kundu

Back in 1985, Wang and Ziller obtained a complete classification of all homogeneous spaces of compact simple Lie groups on which the standard or Killing metric is Einstein. The list consists, beyond isotropy irreducible spaces, of 12…

Differential Geometry · Mathematics 2023-01-03 Emilio A. Lauret , Jorge Lauret

Bi-spinor and G-structure methods are used to classify the possible consistent truncations of type II supergravity to $d=6$ Einstein-Maxwell (gauged) supergravity, and its consistent sub-sectors. In the absence of R-symmetry gauging and a…

High Energy Physics - Theory · Physics 2025-11-05 Niall T. Macpherson , Ricardo Stuardo

This paper consists of two results dealing with balanced metrics (in S. Donaldson terminology) on nonconpact complex manifolds. In the first one we describe all balanced metrics on Cartan domains. In the second one we show that the only…

Differential Geometry · Mathematics 2012-04-16 Andrea Loi , Michela Zedda

We prove the following statement: Let g be a light-line-complete pseudo-Riemannian Einstein metric of indefinite signature on a connected (n>2)-dimensional manifold M. Assume that a conformally equivalent metric is also Einstein. Then, the…

Differential Geometry · Mathematics 2011-08-08 Volodymyr Kiosak , Vladimir S. Matveev

Recently a general prescription for determining the vacuum modular flow generator and the corresponding modular Hamiltonian in the BMS-invariant field theories (BMSFTs) have provided by Apolo et. al \cite{Apolo}. According to this paper…

High Energy Physics - Theory · Physics 2022-05-11 M. R. Setare , M. Koohgard

A new infinite series of Einstein metrics is constructed explicitly on S^2 x S^3, and the non-trivial S^3-bundle over S^2, containing infinite numbers of inhomogeneous ones. They appear as a certain limit of a nearly extreme 5-dimensional…

High Energy Physics - Theory · Physics 2009-11-10 Yoshitake Hashimoto , Makoto Sakaguchi , Yukinori Yasui

We analyse in a systematic way the (non-)compact n-dimensional Einstein Weyl spaces equipped with a cohomogeneity-one metric. With no compactness hypothesis, we prove that, as soon as the (n-1)-dimensional space is an homogeneous reductive…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Guy Bonneau

In this paper we construct Einstein spaces with negative Ricci curvature in various dimensions. These spaces -- which can be thought of as generalised AdS spacetimes -- can be classified in terms of the geometry of the horospheres in…

High Energy Physics - Theory · Physics 2008-11-26 Sigbjorn Hervik

We consider homogeneous hypercomplex manifolds with a transitive action of a compact Lie group and we give a characterization of invariant HKT metrics on them. On every such hypercomplex manifold we prove the existence of an invariant…

Differential Geometry · Mathematics 2026-04-27 Lucio Bedulli , Lorenzo Marcocci

We construct indefinite Einstein solvmanifolds that are standard, but not of pseudo-Iwasawa type. Thus, the underlying Lie algebras take the form $\mathfrak{g}\rtimes_D\mathbb{R}$, where $\mathfrak{g}$ is a nilpotent Lie algebra and $D$ is…

Differential Geometry · Mathematics 2024-06-27 Diego Conti , Federico A. Rossi , Romeo Segnan Dalmasso

We prove that the normal metric on the homogeneous space $E_7/\mathrm{PSO}(8)$ is stable with respect to the Einstein-Hilbert action, thereby exhibiting the first known example of a non-symmetric metric of positive scalar curvature with…

Differential Geometry · Mathematics 2023-08-08 Paul Schwahn , Uwe Semmelmann , Gregor Weingart

We introduce the notion of coarse metric. Every coarse metric induces a coarse structure on the underlying set. Conversely, we observe that all coarse spaces come from a particular type of coarse metric in a unique way. In the case when the…

Metric Geometry · Mathematics 2020-12-15 Chi-Keung Ng

Two geometric inequalities are established for Einstein totally real submanifolds in a complex space form. As immediate applications of these inequalities, some non-existence results are obtained.

Differential Geometry · Mathematics 2016-11-14 Pan Zhang , Liang Zhang , Mukut Mani Tripathi

The double tetrahedron is the triangulation of the three-sphere gotten by gluing together two congruent tetrahedra along their boundaries. As a piecewise flat manifold, its geometry is determined by its six edge lengths, giving a notion of…

Differential Geometry · Mathematics 2010-07-02 Daniel Champion , David Glickenstein , Andrea Young