Abstract
The Goldberg–Sachs theorem is generalized for all four-dimensional manifolds endowed with torsion-free connection compatible with the metric, the treatment includes all signatures as well as complex manifolds. It is shown that when the Weyl tensor is algebraically special severe geometric restrictions are imposed. In particular it is demonstrated that the simple self-dual eigenbivectors of the Weyl tensor generate integrable isotropic planes. Another result obtained here is that if the self-dual part of the Weyl tensor vanishes in a Ricci-flat manifold of (2,2) signature the manifold must be Calabi–Yau or symplectic and admits a solution for the source-free Einstein–Maxwell equations.
Similar content being viewed by others
Notes
In this paper the term “complexified manifold” means a manifold in which the metric can be complex, so that the Weyl tensor is also generally complex. The here called “real manifolds” are the ones with real metric and, consequently, real Weyl tensor. In general the tangent bundle of the real manifolds will be assumed to be complexified. Finally, the term “complex manifold” will mean a manifold that can be covered by complex charts with analytic transition functions, these manifolds are sometimes called Hermitian.
Throughout this and the next section the Ricci tensor will always be assumed to vanish. Also the tangent bundle is assumed to be endowed with a torsion-free connection compatible with the metric (Levi-Civita), only this kind connection is considered in this article.
Note that \(e^{1}_{\mu } =e_{3\,\mu },\, e^{2}_{\mu } =-e_{4\,\mu },\, e^{3}_{\mu } =e_{1\,\mu }\) and \(e^{4}_{\mu } =-e_{2\,\mu }\).
Where by complex manifold it is meant a manifold which over the complex field can be covered by charts with analytic transition functions.
Actually a Calabi–Yau manifold is defined to be a Kähler manifold with vanishing first Chern class. When the Ricci tensor is zero the first Chern class vanishes trivially. Conversely, it can be proved that a Kähler manifold with vanishing first Chern class admits a Ricci-flat metric.
Note that if \(\omega _{12}=0,\, \omega _{43}=0\) and \(\omega _{24}=\omega _{13}\) then all the isotropic distributions \(\{ae_1+be_4,ae_2+be_3\}\) for \(a,b\) constants are integrable. Thus anti-self-dual manifolds admit infinitely many integrable self-dual isotropic distributions.
Meaning that the manifold over the complex field can be covered by charts with analytic transition functions.
In the Newman-Penrose formalism the shear parameter is given by \(\sigma =\omega _{212}\), which is zero in the considered case.
For instance, reference [33] proved that the repeated PNDs of 5-dimensional Myers-Perry black hole are not shear-free.
In CMPP classification the WANDs are natural higher-dimensional analogues of the four-dimensional PNDs [32].
References
Petrov, A.Z.: The classification of spaces definig gravitational fields. Gen. Relativ. Gravit. 32, 1665 (2000). This is a translated republication of original 1954 paper
Stephani, H., et al.: Exact Solutions of Einstein’s field Equations. Cambridge University Press, Cambridge (2009)
Kerr, R.P.: Gravitational field of a spinning mass as an example of algebraically special metrics. Phys. Rev. Lett. 11, 237 (1963)
Goldberg, J., Sachs, R.: A theorem on Petrov types. Gen. Relativ. Gravit. 41, 433 (2009). This is a republication of original 1962 paper
Batista, C.: Weyl tensor classifcation in four-dimensional manifolds of all signatures. Gen. Relativ. Gravit. (2013). doi:10.1007/s10714-013-1499-8. Available at arXiv:1204.5133
Plebański, J.F., Hacyan, S.: Null geodesic surfaces and Goldberg-Sachs theorem in complex Riemannian spaces. J. Math. Phys. 16, 2403 (1975)
Przanowski, M., Broda, B.: Locally Kähler gravitational instantons. Acta Physica Polonica B14, 637 (1983)
Nurowski, P., Trautman, A.: Robinson manifolds as the Lorentzian analogs of Hermite Manifolds. Differ Geom Appl 17, 175 (2002)
Gover, A., Hill, C., Nurowski, P.: Sharp version of the Goldberg–Sachs theorem. Annali di Matematica Pura ed Applicata 190 Number 2, 295 (2011). Available at arXiv:0911.3364
Durkee, M., Reall, H.S.: A higher-dimensional generalization of the geodesic part of the Goldberg–Sachs theorem. Class. Quantum Grav. 26, 245005 (2009). Available at arXiv:0908.2771
Ortaggio, M., et al.: On a five-dimensional version of the Goldberg-Sachs theorem. Available at arXiv:1205.1119
Taghavi-Chabert, A.: Optical structures, algebraically special spacetimes and the Goldberg-Sachs theorem in five dimensions. Class. Quantum Grav. 28, 145010 (2011). Available at arXiv:1011.6168
Taghavi-Chabert, A.: The complex Goldberg-Sachs theorem in higher dimensions. J. Geom. Phys. 62, 981 (2012). Available at arXiv:1107.2283
Law, P.R.: Neutral Einstein metrics in four dimensions. J. Math. Phys. 32, 3039 (1991)
Coley, A., Hervik, S.: Higher dimensional bivectors and classification of the Weyl operator. Class. Quantum Grav. 27, 015002 (2010). Available at arXiv:0909.1160
Hervik, S., Coley, A.: Curvature operators and scalar curvature invariants. Class. Quantum Grav. 27, 095014 (2010). Available at arXiv:1002.0505
Plebański, J.: Some solutions of complex Einstein equations. J. Math. Phys. 16, 2395 (1975)
Hacyan, S.: Gravitational instantons in H-spaces. Phys. Lett. 75A, 23 (1979)
Law, P.R.: Classification of the Weyl curvature spinors of neutral metrics in four dimensions. J. Geom. Phys. 56, 2093 (2006)
Hervik, S., Coley, A.: On the algebraic classification of pseudo-Riemannian spaces. Int. J. Geom. Methods Mod. Phys. 8, 1679 (2011). Available at arXiv:1008.3021
Penrose, R., Rindler, W.: Spinors and space-time vol. 1 and 2, Cambridge University Press, Cambridge (1984 and 1986)
Bel, L.: Radiation states and the problem of energy in general relativity. Gen. Relativ. Gravit. 32, 2047 (2000) Reprint of a 1962 paper
Robinson, I., Schild, A.: Generalization of a theorem by Goldberg and Sachs. J. Math. Phys. 4, 484 (1963)
Kopczynski, W., Trautman, A.: Simple spinors and real structures. J. Math. Phys. 33, 550 (1992)
Nakahara, M.: Geometry, Topology and Physics. Taylor & Francis, London (2003)
Newlander, A., Nirenberg, L.: Complex analytic coordinates in almost complex manifolds. Ann. Math. 65, 391 (1957)
Wald, R.M.: General Relativity. The University of Chicago Press, Chicago (1984)
Kinnersley, W.: Type D vacuum metrics. J. Math. Phys. 10, 1195 (1969)
Ivanov, S., Zamkovoy, S.: Parahermitian and paraquaternionic manifolds. Differ. Geom. Appl. 23, 205 (2005). Available at arXiv:math/0310415
McIntosh, C., Hickman, M.: Complex relativity and real solutions. I: Introduction. Gen. Relativ. Gravit. 17, 111 (1985)
Mason, L., Woodhouse, N.: Integrability, self-duality and twistor theory. Oxford University Press, Oxford (1996)
Coley, A., Milson, R., Pravda, V., Pravdová, A.: Classification of the Weyl Tensor in higher dimensions. Class. Quantum Grav. 21, L-35 (2004). Available at arXiv:gr-qc/0401008
Frolov, V., Stojković, D.: Particle and light motion in a space-time of a five-dimensional black hole. Phys. Rev. D 68, 064011 (2003). Available at arXiv:gr-qc/0301016
Berkovits, N., Marchioro, D.: Relating the Green–Schwarz and pure spinor formalisms for the superstring. J. High Energy Phys. 01(2005). Available at arXiv:hep-th/0412198.
Acknowledgments
I want to thank Bruno G. Carneiro da Cunha for the encouragement and for the manuscript revision. This research was supported by CNPq(Conselho Nacional de Desenvolvimento Científico e Tecnológico).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Batista, C. A Generalization of the Goldberg–Sachs theorem and its consequences. Gen Relativ Gravit 45, 1411–1431 (2013). https://doi.org/10.1007/s10714-013-1539-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10714-013-1539-4