Speaker
Description
We briefly review the properties of static, spherically symmetric configurations of general relativity with a minimally coupled scalar field $\phi$ whose kinetic energy is negative in a restricted (strong-field) region of space and positive outside it [1--3]. This ``trapped ghost'' concept may in principle explain why no ghosts are observed under usual, weak-field conditions. The configurations considered are wormholes and regular black holes without a center, in particular, black universes (black holes with an expanding cosmology beyond the event horizon) [4--6]. Spherically symmetric perturbations of these objects are considered,
and it is stressed that, due to the universal shape of the effective potential near a transition surface from canonical to phantom behavior of the scalar field, such surfaces restrict the possible perturbations and play a stabilizing role.
[1] K.A. Bronnikov and S.V. Sushkov, “Trapped ghosts: a new class of wormholes,” Class. Quantum Grav. 27, 095022 (2010); arXiv: 1001.3511.
[2] K.A. Bronnikov and E.V. Donskoy, “Black universes with trapped ghosts.” Grav. Cosmol. 17, 176–180 (2011).
[3] K.A. Bronnikov, E.V. Donskoy, and P. Korolyov, “Magnetic wormholes and black universes with trapped ghosts,” Vestnik RUDN No. 2, 139–149 (2013).
[4] K.A.BronnikovandJ.C.Fabris,“Regularphantomblackholes,”Phys.Rev.Lett.96,251101 (2006); gr-qc/0511109.
[5] S.V. Bolokhov, K.A. Bronnikov, and M.V. Skvortsova, “Magnetic black universes and worm- holes with a phantom scalar,” Class. Quantum Grav. 29, 245006 (2012); arXiv: 1208.4619.
[6] K. A. Bronnikov and S. G. Rubin, Black Holes, Cosmology, and Extra Dimensions (World Scientific, Singapore, 2012).
| Type of contribution | Invited talk |
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