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

Gravitating Fermionic Lumps with a False Vacuum Core

We investigate gravitating lumps with a false vacuum core surrounded by the true vacuum in a scalar field potential. Such configurations become possible in the Einstein gravity in the presence of fermions at the core. Gravitational interactions as well as Yukawa interactions are essential for such lumps to exist. The mass and size of gravitating lumps sensitively depend on the scale characterizing the scalar field potential and the density of fermions. These objects can exist in the universe at various scales.Comment: 17 pages, 16 figures. Final published versio

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