Date of Original Version
© The Author(s) 2011 This is an electronic version of an article published by Oxford University Press. The version of record is available online at http://dx.doi.org/10.1093/amrx/abr007
Abstract or Description
We investigate spectral stability of vortex solutions of the Gross–Pitaevskii equation, a mean-field approximation for Bose–Einstein condensates in an effectively two-dimensional axisymmetric harmonic trap. We study eigenvalues of the linearization both rigorously and through computation of the Evans function, a sensitive and robust technique whose use we justify mathematically. The absence of unstable eigenvalues is justified a posteriori through the use of the Krein signature of purely imaginary eigenvalues, which can also be used to significantly reduce computational effort. In particular, we prove general basic continuation results on Krein signature for finite systems of eigenvalues in infinite-dimensional problems.
Applied Mathematics Research Express, 2012, 1, 1-46.