A Broken Degeneracy in the Resistive MHD Spectrum

We present work relating to features in the stable resistive MHD spectrum, which is qualitatively different from the ideal MHD spectrum even for vanishing resistivity. In the cases under consideration stable eigenvalues are spaced along loci in the complex plane. The loci become densely populated with eigenvalues as the resistivity increases. We examine the eigenvalue spectrum of a cylindrical model and relate apparently conflicting results about the shape of the locus. In particular, in a specific model we show how a broken degeneracy produces a pair of precursor loci which converge towards the infinitesimal resistivity locus. We also examine the effects of compressibility on this spectrum, in order to demonstrate the qualitative difference between compressible and incompressible spectra