Publication date: Dec 2010
Abstract:
Current-carrying string loop dynamics in Schwarzschild-de Sitter
spacetimes characterized by the cosmological parameter
λ=(1)/(3)ΛM2 is investigated. With attention concentrated to
the axisymmetric motion of string loops it is shown that the resulting
motion is governed by the presence of an outer tension barrier and an
inner angular momentum barrier that are influenced by the black hole
gravitational field given by the mass M and the cosmic repulsion given
by the cosmological constant Λ. The gravitational attraction could cause
capturing of the string having low energy by the black hole or trapping
in its vicinity; with high enough energy, the string can escape
(scatter) to infinity. The role of the cosmic repulsion becomes
important in vicinity of the so-called static radius where the
gravitational attraction is balanced by the cosmic repulsion—it is
demonstrated both in terms of the effective potential of the string
motion and the basin boundary method reflecting its chaotic character,
that a potential barrier exists along the static radius behind which no
trapped oscillations may exist. The trapped states of the string loops,
governed by the interplay of the gravitating mass M and the cosmic
repulsion, are allowed only in Schwarzschild-de Sitter spacetimes with
the cosmological parameter λ<λtrap̃0.00497. The trapped
oscillations can extend close to the radius of photon circular orbit,
down to rmt̃3.3M.
Authors:
Kološ, M.; Stuchlík, Z.;