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We prove that higher dimensional Einstein spacetimes which possess a geodesic, non-degenerate double Weyl aligned null direction (WAND) $\ell$ must additionally possess a second double WAND (thus being of type D) if either: (a) the Weyl…

General Relativity and Quantum Cosmology · Physics 2018-03-08 Marcello Ortaggio , Vojtěch Pravda , Alena Pravdová

Vacuum solutions admitting a hypersurface-orthogonal repeated principal null direction are an important class of 4d algebraically special spacetimes. We investigate the 5d analogues of such solutions: vacuum spacetimes admitting a…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Harvey S. Reall , Alexander A. H. Graham , Carl P. Turner

In more than four spacetime dimensions, a multiple Weyl-aligned null direction (WAND) need not be geodesic. It is proved that any higher-dimensional Einstein spacetime admitting a non-geodesic multiple WAND also admits a geodesic multiple…

General Relativity and Quantum Cosmology · Physics 2010-01-04 Mark Durkee , Harvey S. Reall

This short note shows that many of the results derived by Pravda et al (Class. Quant. Grav. 24 4407-4428) for higher-dimensional Type D Einstein spacetimes can be generalized to all Einstein spacetimes admitting a multiple WAND; the main…

General Relativity and Quantum Cosmology · Physics 2009-10-02 Mark Durkee

We determine the general form of the solutions of the five-dimensional vacuum Einstein equations with cosmological constant for which (i) the Weyl tensor is everywhere type II or more special in the null alignment classification of Coley et…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Gabriel Bernardi de Freitas , Mahdi Godazgar , Harvey S. Reall

We present an algebraic classification, based on the null alignment properties of the Weyl tensor, of the general Kundt class of spacetimes in arbitrary dimension for which the non-expanding, non-twisting, shear-free null direction \boldk…

General Relativity and Quantum Cosmology · Physics 2013-06-19 Jiri Podolsky , Robert Svarc

Previous work has found a higher-dimensional generalization of the "geodesic part" of the Goldberg-Sachs theorem. We investigate the generalization of the "shear-free part" of the theorem. A spacetime is defined to be algebraically special…

General Relativity and Quantum Cosmology · Physics 2012-09-18 Marcello Ortaggio , Vojtech Pravda , Alena Pravdova , Harvey S. Reall

We show that all static spacetimes in higher dimensions are of Weyl types G, I_i, D or O. This applies also to stationary spacetimes if additional conditions are fulfilled, as for most known black hole/ring solutions. (The conclusions…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Vojtech Pravda , Alena Pravdova , Marcello Ortaggio

After a concise overview of Einstein spacetimes of type II (or more special) in four and five dimensions, we summarize recent results in the six-dimensional case. We assume the optical matrix to be non-degenerate and ``generic'', and the…

General Relativity and Quantum Cosmology · Physics 2026-02-23 David Kokoška , Marcello Ortaggio

Algebraic classification of higher dimensional, shear-free, twist-free, expanding (or non-expanding) spacetime is studied with the limit of $D\rightarrow\infty$. Similar to classification of any arbitrary dimension $D>4$, this spacetime is…

General Relativity and Quantum Cosmology · Physics 2023-09-07 Pınar Kirezli

We study the geometrical properties of null congruences generated by an aligned null direction of the Weyl tensor (WAND) in spacetimes of the Weyl and Ricci type N (possibly with a non-vanishing cosmological constant) in an arbitrary…

General Relativity and Quantum Cosmology · Physics 2016-06-06 Martin Kuchynka , Alena Pravdova

We study a generalization of the "shear-free part" of the Goldberg-Sachs theorem for Einstein spacetimes admitting a non-twisting multiple Weyl Aligned Null Direction (WAND) l in n>=6 spacetime dimensions. The form of the corresponding…

General Relativity and Quantum Cosmology · Physics 2013-03-13 Marcello Ortaggio , Vojtěch Pravda , Alena Pravdová

We study a class of higher dimensional warped Einstein spacetimes with one extra dimension. These were originally identified by Brinkmann as those Einstein spacetimes that can be mapped conformally on other Einstein spacetimes, and have…

General Relativity and Quantum Cosmology · Physics 2011-04-08 Marcello Ortaggio , Vojtech Pravda , Alena Pravdova

We determine the most general solution of the five-dimensional vacuum Einstein equation, allowing for a cosmological constant, with (i) a Weyl tensor that is type II or more special in the classification of Coley et al., (ii) a…

General Relativity and Quantum Cosmology · Physics 2015-01-14 Gabriel Bernardi de Freitas , Mahdi Godazgar , Harvey S. Reall

We refine the null alignment classification of the Weyl tensor of a five-dimensional spacetime. The paper focusses on the algebraically special alignment types {\bf {N}}, {\bf {III}}, {\bf {II}} and {\bf {D}}, while types {\bf {I}} and {\bf…

General Relativity and Quantum Cosmology · Physics 2012-09-25 Alan Coley , Sigbjorn Hervik , Marcello Ortaggio , Lode Wylleman

We study the class of vacuum (Ricci flat) six-dimensional spacetimes admitting a non-degenerate multiple Weyl aligned null direction l, thus being of Weyl type II or more special. Subject to an additional assumption on the asymptotic…

General Relativity and Quantum Cosmology · Physics 2017-06-26 Marcello Ortaggio

Vacuum spacetimes admitting a non-twisting geodetic multiple Weyl aligned null direction (WAND) are analyzed in arbitrary dimension using recently developed higher-dimensional Newman-Penrose (NP) formalism. We determine dependence of the…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Alena Pravdova , Vojtech Pravda

General properties of Kerr-Schild spacetimes with (A)dS background in arbitrary dimension are studied. It is shown that the geodetic Kerr-Schild vector k is a multiple WAND of the spacetime. Einstein Kerr-Schild spacetimes with…

General Relativity and Quantum Cosmology · Physics 2011-05-13 Tomáš Málek , Vojtěch Pravda

The Sachs equations governing the evolution of the optical matrix of geodetic WANDs (Weyl aligned null directions) are explicitly solved in n-dimensions in several cases which are of interest in potential applications. This is then used to…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Marcello Ortaggio , Vojtech Pravda , Alena Pravdova

Einstein spacetimes (that is vacuum spacetimes possibly with a non-zero cosmological constant {\Lambda}) with constant non-zero Weyl eigenvalus are considered. For type Petrov II & D this assumption allows one to prove that the non-repeated…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Alan Barnes
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