Abstract
We argue that the well-known geodesic completeness property of pp-waves can be disregarded once the geodesics are extracted as being extended along sets of Brinkmann coordinates. We investigate this issue in the more general context of congruence convergence and show that the problem leads to various issues for nongeodesic congruences. Our consideration is mostly based on the null congruence expansion, and we also provide a generalized Raychaudhuri equation.
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References
A. Einstein, “Zum gegenwärtigen Stande des Gravitationsproblems,” Phys. Z., 14, 1249–1262 (1913).
C. W. Misner, K. S. Thorne, and J. A. Wheeler, Gravitation, W. H. Freeman, San Francisco, Calif. (1973).
B. P. Abbott et. al [LIGO Scientific Collab. and Virgo Collab.], “Observation of gravitational waves from a binary black hole merger,” Phys. Rev. Lett., 116, 06110 (2016).
L. Ryder, Introduction to General Relativity, Cambridge Univ. Press, Cambridge (2009).
B. F. Schutz, A First Course in General Relativity, Cambridge Univ. Press, Cambridge (2009).
H. W. Brinkmann, “Einstein spaces which are mapped conformally on each other,” Math. Ann., 94, 119–145 (1925).
O. R. Baldwin and G. B. Jeffery, “The relativity theory of plane waves,” Proc. R. Soc. London A, 111, 95–104 (1926).
J. Ehlers and W. Kundt, “Exact solutions of the gravitational field equations,” in: The Theory of Gravitation (L. Witten, ed.), Wiley, New York (1962), pp. 49–101.
H. Stephani, D. Krame, M. Maccallum, C. Hoenselares, and E. Herlt, Exact Solutions of Einstein’s Field Equations, Cambridge Univ. Press, Cambridge (2003).
J. W. van Holten, “Gravitational waves and black holes,” Fortschr. Phys., 45, 439–516 (1997).
G. S. Hall, Symmetries and Curvature Structure in General Relativity (World Sci. Lect. Notes Phys., Vol. 46), World Scientific, Singapore (2004).
J. L. Flores and M. Sánchez, “On the geometry of pp-wave type spacetimes,” in: Analytical and Numerical Approaches to Mathematical Relativity (Lect. Notes Phys., Vol. 692, J. Frauendiener, D. J. W. Giulini, and V. Perlick, eds.), Springer, Berlin (2006), pp. 79–98.
M. Gürses and M. Halil, “pp-Waves in the generalized Einstein theories,” Phys. Lett. A, 68, 182–184 (1978).
A. Bayka, “pp-Waves in modified gravity,” Turk. J. Phys., 40, 77–11 (2016); arXiv:1510.00522v5 [gr-qc] (2015).
H-J. Schmidt, “A two-dimensional representation of four-dimensional gravitational waves,” Internat. J. Modern Phys. D, 7, 215–223 (1998).
V. Daftardar-Gejji, “On conformally related pp-waves,” Pramana, 56, 591–596 (2001).
A. J. Keane and B. O. J. Tuppe, “Conformal symmetry classes for pp-wave spacetimes,” Class. Q. Grav., 21, 2037–2064 (2004).
H. Singh, “Generalised Penrose limits and pp-waves,” Phys. Lett. B, 583, 315–323 (2004).
J. D. Steele, “On generalised p.p. waves,” https://www.scribd.com/document/78988658/J-D-Steele-On-Generalised-p-p-waves (2010).
B. Cropp and M. Visser, “Polarization modes for strong-field gravitational waves,” J. Phys.: Conf. Ser., 314, 012073 (2011).
R. Milson, D. McNutt, and A. Coley, “Invariant classification of vacuum pp-waves,” J. Math. Phys., 54, 022502 (2013).
R. Cianci, L. Fabbri, and S. Vignolo, “Exact solutions for Weyl fermions with gravity,” Eur. Phys. J. C, 75, 478 (2015).
E. Poisson, A Relativist’s Toolkit: The Mathematics of Black-Hole Mechanics, Cambridge Univ. Press, Cambridge (2009).
V. Faraoni, Cosmological and Black Hole Apparent Horizons, Springer, Cham (2015).
S. Kar and S. Sengupta, “The Raychaudhuri equations: A brief review,” Pramana, 69, 49–76 (2007).
M. Fathi and M. Mohseni, “Gravitational collapse in repulsive R+μ4/R gravity,” Eur. Phys. J. Plus, 131, 360 (2016).
R. Penrose, “Gravitational collapse and space–time singularities,” Phys. Rev. Lett., 14, 57–59 (1965).
S. W. Hawking, “Occurrence of singularities in open Universes,” Phys. Rev. Lett., 15, 689–690 (1965).
S. W. Hawking, “Singularities in the Universe,” Phys. Rev. Lett., 17, 444–445 (1966).
R. Penrose, “Gravitational collapse: The role of general relativity,” Gen. Relat. Grav., 34, 1141–1165 (2002).
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Most textbooks on general relativity provide extensive information on linearized gravity and the TT gauge (see, e.g., the relevant chapters in [2], [4], [5]).
Prepared from an English manuscript submitted by the authors; for the Russian version, see Teoreticheskaya i Matematicheskaya Fizika, Vol. 195, No. 2, pp. 269–287, May, 2018.
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Fathi, M., Mohseni, M. Congruence Convergence in Pp-Wave Space–Time. Theor Math Phys 195, 729–744 (2018). https://doi.org/10.1134/S0040577918050082
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DOI: https://doi.org/10.1134/S0040577918050082