2 research outputs found
On the radial linear stability of nonrelativistic -boson stars
We study the linear stability of nonrelativistic -boson stars,
describing static, spherically symmetric configurations of the
Schr\"odinger-Poisson system with multiple wave functions having the same value
of the angular momentum . In this work we restrict our analysis to
time-dependent perturbations of the radial profiles of the wave
functions, keeping their angular dependency fixed. Based on a combination of
analytic and numerical methods, we find that for each , the ground state
is linearly stable, whereas the 'th excited states possess unstable
(exponentially in time growing) modes. Our results also indicate that all
excited states correspond to saddle points of the conserved energy functional
of the theory.Comment: 21+1 pages, 7 figures, 5 table
Are nonrelativistic ground state -boson stars only stable for and ?
In previous work we analyzed the linear stability of non-relativistic
-boson stars with respect to radial modes and showed that ground state
configurations are stable with respect to these modes, whereas excited states
are unstable. In this work we extend the analysis to non-spherical linear mode
perturbations. To this purpose, we expand the wave function in terms of tensor
spherical harmonics which allows us to decouple the perturbation equations into
a family of radial problems. By using a combination of analytic and numerical
methods, we show that ground state configurations with possess
exponentially in time growing non-radial modes, whereas only oscillating modes
are found for and . This leads us to conjecture that
nonrelativistic -boson stars in their ground state are stable for
as well as , while ground state and excited configurations
with are unstable.Comment: 21 pages, 5 figures, 2 table