Publication date: Sep 2015
Abstract:
We construct perfect fluid tori in the field of the Kehagias-Sfetsos
(K-S) naked singularities. These are spherically symmetric vacuum
solutions of the modified Hořava quantum gravity, characterized by a
dimensionless parameter ω M^2, combining the gravitational mass
parameter M of the spacetime with the Hořava parameter ω reflecting the
role of the quantum corrections. In dependence on the value of ω M^2,
the K-S naked singularities demonstrate a variety of qualitatively
different behavior of their circular geodesics that is fully reflected
in the properties of the toroidal structures, demonstrating clear
distinction to the properties of the torii in the Schwarzschild
spacetimes. In all of the K-S naked singularity spacetimes the tori are
located above an „antigravity“ sphere where matter can stay in a stable
equilibrium position, which is relevant for the stability of the
orbiting fluid toroidal accretion structures. The signature of the K-S
naked singularity is given by the properties of marginally stable tori
orbiting with the uniform distribution of the specific angular momentum
of the fluid, l= const. In the K-S naked singularity spacetimes with ω
M^2 > 0.2811, doubled tori with the same l= const can exist; mass
transfer between the outer torus and the inner one is possible under
appropriate conditions, while only outflow to the outer space is allowed
in complementary conditions. In the K-S spacetimes with ω M^2 <
0.2811, accretion from cusped perfect fluid tori is not possible due to
the non-existence of unstable circular geodesics.
Authors:
Stuchlík, Z.; Pugliese, D.; Schee, J.; Kučáková, H.;