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.;