**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.;