“…(1987), the perturbations are given by It is known that axisymmetric perturbations without a fixed volume constraint are more dangerous than non-axisymmetric ones (Myshkis et al. 1987; Slobozhanin & Alexander 2003). Because the perturbations for the exotic cylinders are unconstrained, only the axisymmetric perturbation needs to be analysed in the study of stability, which leads to an eigenvalue problem (Myshkis et al.…”