Abstract
We analyze the space-times admitting two shear-free geodesic null congruences. The integrability conditions are presented in a plain tensorial way as equations on the volume element U of the time-like 2-plane that these directions define. From these we easily deduce significant consequences. We obtain explicit expressions for the Ricci and Weyl tensors in terms of U and its first and second order covariant derivatives. We study the different compatible Petrov-Bel types and give the necessary and sufficient conditions that characterize every type in terms of U. The type D case is analyzed in detail and we show that every type D space-time admitting a 2 + 2 conformal Killing tensor also admits a conformal Killing-Yano tensor.
Similar content being viewed by others
References
Ferrando J.J. and Sáez J.A. (2004). J. Math. Phys. 45: 652
Hauser J. and Malhiot R.J. (1976). J. Math. Phys. 17: 1306
Dietz W. and Rüdiger R. (1980). Gen. Rel. Grav. 12: 545
Ferrando J.J. and Sáez J.A. (2003). Gen. Relativ. Gravit. 35: 1191
Coll B., Ferrando J.J. and Sáez J.A. (2006). J. Math. Phys. 47: 062503
Collinson C.D. (1976). Int. J. Thor. Phys. 15: 311
Stephani H. (1978). Gen. Relativ. Gravit. 9: 789
Walker M. and Penrose R. (1970). Commun. Math. Phys. 18: 265
Naveira A.M. (1983). Rend. Mat. 3: 577
Gil-Medrano O. (1983). Rend. Cir. Mat. Palermo Ser. II 32: 315
Coll, B., Ferrando, J.J.: Almost-Product structures in relativity. Recents developments in Gravitation, Proceeding of the Relativisty Meeting-89. World Scientific, Singapore, p. 338 (1990)
Rainich G.Y. (1925). Trans. Am. Math. Soc. 27: 106
Coll B., Fayos F. and Ferrando J.J. (1987). J. Math. Phys. 28: 1075
Debever R. (1976). Bull. Acad. R. Belgique 62: 662
Ferrando, J.J., Sáez, J.A.: (in preparation)
Ferrando J.J., Morales J.A. and Sáez J.A. (2001). Class. Quantum Grav. 18: 4969
Ferrando J.J. and Sáez J.A. (1997). Class. Quantum Grav. 14: 129
Ferrando J.J. and Sáez J.A. (1998). Class. Quantum Grav. 15: 1323
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ferrando, J.J., Sáez, J.A. On the space-times admitting two shear-free geodesic null congruences. Gen Relativ Gravit 39, 343–359 (2007). https://doi.org/10.1007/s10714-006-0388-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10714-006-0388-9