**Publication date:** Jul 2005

**Abstract:**

Relativistic Keplerian orbital frequency (νK) and related

epicyclic frequencies (radial νr, vertical

νθ) play an important role in the physics of

accretion discs orbiting Kerr black holes – quasiperiodic oscillations

observed in microquasars can be explained by associated resonant or

trapping effects. Because of growing theoretical evidence of the

possible existence of naked singularities, we discuss the behaviour of

the fundamenal orbital frequencies for Keplerian motion in the field of

Kerr naked singularities, primarily in order to find phenomena that

could observationally distinguish a hypothetical naked singularity from

black holes. Some astrophysically important consequences are sketched,

namely the existence of strong resonant frequency for all Kerr naked

singularities, with radial and vertical epicyclic frequencies equal and

given by the relation ω_sr = a-2√{a^2-1} (a^2+1

)-1.

**Authors:**

Török, G.; Stuchlík, Z.;