Abstract
An overview of the currently available methods for finding the unstable modes of a stellar disk within the framework of linear perturbation theory is given. The galaxy models with gradually rising and flat rotation curves are used as examples to show the existence of various kinds of spectra of unstable modes. The peculiarities of the spectra are discussed. The spectrum of the model with a (flat) rotation curve rapidly rising at the center is provided for the first time. The method that relies on a biorthogonal basis expansion of the perturbed potential and surface density is shown to have limited applicability due to the shortage of appropriate basis functions. The finite element method successfully applied in other areas of science and engineering is sensitive in its current implementation to the presence of regions with resonant orbits.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
