28 research outputs found
False Vacuum Lumps with the Fermionic Core
Stable gravitating lumps with a false vacuum core surrounded by the true
vacuum in a scalar field potential exist in the presence of fermions at the
core. These objects may exist in the universe at various scales.Comment: 3 pages, 4 figures. To appear in the proceedings of the Tenth Marcel
Grossmann Meeting on General Relativit
Asymptotic Spectrum of Kerr Black Holes in the Small Angular Momentum Limit
We study analytically the highly damped quasinormal modes of Kerr black holes
in the small angular momentum limit. To check the previous analytic
calculations in the literature, which use a combination of radial and tortoise
coordinates, we reproduce all the results using the radial coordinate only.
According to the earlier calculations, the real part of the highly damped
quasinormal mode frequency of Kerr black holes approaches zero in the limit
where the angular momentum goes to zero. This result is not consistent with the
Schwarzschild limit where the real part of the highly damped quasinormal mode
frequency is equal to c^3 ln(3)/(8 pi G M). In this paper, our calculations
suggest that the highly damped quasinormal modes of Kerr black holes in the
zero angular momentum limit make a continuous transition from the Kerr value to
the Schwarzschild value. We explore the nature of this transition using a
combination of analytical and numerical techniques. Finally, we calculate the
highly damped quasinormal modes of the extremal case in which the topology of
Stokes/anti-Stokes lines takes a different form.Comment: 13 pages, 6 figure
The Highly Damped Quasinormal Modes of Extremal Reissner-Nordstr\"om and Reissner-Nordstr\"om-de Sitter Black Holes
We analyze in detail the highly damped quasinormal modes of -dimensional
extremal Reissner-Nordstrm and
Reissner-Nordstrm-de Sitter black holes. We only consider the
extremal case where the event horizon and the Cauchy inner horizon coincide. We
show that, even though the topology of the Stokes/anti-Stokes lines in the
extremal case is different than the non-extremal case, the highly damped
quasinormal mode frequencies of extremal black holes match exactly with the
extremal limit of the non-extremal black hole quasinormal mode frequencies.Comment: 17 pages, 5 figure