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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

Consensus algorithms are popular distributed algorithms for computing aggregate quantities, such as averages, in ad-hoc wireless networks. However, existing algorithms mostly address the case where the measurements lie in a Euclidean space.…

Dynamical Systems · Mathematics 2012-02-02 Roberto Tron , Bijan Afsari , René Vidal

We prove that the Einstein equations can be solved in a very general form for arbitrary spacetime dimensions and various types of vacuum and non-vacuum cases following a geometric method of anholonomic frame deformations for constructing…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Sergiu I. Vacaru

Reflection in a line in Euclidean 3-space defines an almost paracomplex structure on the space of all oriented lines, isometric with respect to the canonical neutral Kaehler metric. Beyond Euclidean 3-space, the space of oriented geodesics…

Differential Geometry · Mathematics 2022-05-11 Nikos Georgiou , Brendan Guilfoyle

We introduce Einstein Fields, a neural representation designed to compress computationally intensive four-dimensional numerical relativity simulations into compact implicit neural network weights. By modeling the metric, the core tensor…

Machine Learning · Computer Science 2026-02-10 Sandeep Suresh Cranganore , Andrei Bodnar , Arturs Berzins , Johannes Brandstetter

We give an overview of progress on homogeneous Einstein metrics on large classes of homogeneous manifolds, such as generalized flag manifolds and Stiefel manifolds. The main difference between these two classes of homogeneous spaces is that…

Differential Geometry · Mathematics 2016-05-20 Andreas Arvanitoyeorgos

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

Quantum Einstein Gravity (QEG), nonperturbatively renormalized by means of a certain asymptotically safe renormalization group (RG) trajectory, is explored by solving its scale dependent effective field equations and embedding the family of…

High Energy Physics - Theory · Physics 2023-01-18 Renata Ferrero , Martin Reuter

Considering the scale dependent effective spacetimes implied by the functional renormalization group in d-dimensional Quantum Einstein Gravity, we discuss the representation of entire evolution histories by means of a single, (d +…

High Energy Physics - Theory · Physics 2021-05-12 Renata Ferrero , Martin Reuter

In this article we study self-gravitating static solutions of the Einstein-ScalarField system in arbitrary dimensions. We discuss the existence and the non-existence of geodesically complete solutions depending on the form of the scalar…

General Relativity and Quantum Cosmology · Physics 2016-02-02 Martin Reiris

We present new classes of exact solutions with noncommutative symmetries constructed in vacuum Einstein gravity (in general, with nonzero cosmological constant), five dimensional (5D) gravity and (anti) de Sitter gauge gravity. Such…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Sergiu I. Vacaru

We show that every analytic semi-Riemannian manifold can be isometrically embeddded into an Einstein maifold in co-dimension one.

Mathematical Physics · Physics 2011-06-07 Nikolaos I. Katzourakis

The aim of this paper is to present some structural equations for generalized quasi-Einstein metrics which was defined recently by Catino in [12]. In addition, supposing that the Riemannian manifold is Einstein we shall show that it is a…

Differential Geometry · Mathematics 2012-09-13 Abdênago Barros , Ernani Ribeiro

We consider the problem of reconstructing an embedding of a compact connected Riemannian manifold in a Euclidean space up to an almost isometry, given the information on intrinsic distances between points from its ``sufficiently large''…

Optimization and Control · Mathematics 2024-01-26 Nikita Puchkin , Vladimir Spokoiny , Eugene Stepanov , Dario Trevisan

We prove that the number of complex invariant Einstein metrics on the flag manifold $M_{n_1,n_2,n_3}=SO_{2(n_1+n_2+n_3)+1}/U_{n_1} \times U_{n_2} \times SO_{2n_3+1}$ is equal to 132, except when the parameters $n_1, n_2, n_3$ satisfy one of…

Differential Geometry · Mathematics 2021-09-23 Alexey Lavrov

We formulate an approach to the geometry of Riemann-Cartan spaces provided with nonholonomic distributions defined by generic off-diagonal and nonsymmetric metrics inducing effective nonlinear and affine connections. Such geometries can be…

General Relativity and Quantum Cosmology · Physics 2008-12-19 Sergiu I. Vacaru

In this paper we take the perspective introduced by Case-Shu-Wei of studying warped product Einstein metrics through the equation for the Ricci curvature of the base space. They call this equation on the base the $m$-Quasi Einstein…

Differential Geometry · Mathematics 2011-01-25 Chenxu He , Peter Petersen , William Wylie

Based on a well-known fact that there are no Einstein hypersurfaces in a non-flat complex space form, in this article we study the quasi-Einstein condition, which is a generalization of an Einstein metric, on the real hyersurface of a…

Differential Geometry · Mathematics 2019-09-04 Xiaomin Chen

It is formulated a new 'anholonomic frame' method of constructing exact solutions of Einstein equations with off--diagonal metrics in 4D and 5D gravity. The previous approaches and results are summarized and generalized as three theorems…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru

We prove that for every natural number k there are simply connected topological four-manifolds which have at leat k distinct smooth structures supporting Einstein metrics, and also have infinitely many distinct smooth structures not…

Geometric Topology · Mathematics 2007-05-23 V. Braungardt , D. Kotschick