Unstable Spiral Point

A Fixed Point for which the Stability Matrix has Eigenvalues of the form $\lambda_\pm=\alpha\pm i\beta$ (with $\alpha,\beta>0$).

See also Elliptic Fixed Point (Differential Equations), Fixed Point, Hyperbolic Fixed Point (Differential Equations), Stable Improper Node, Stable Node, Stable Spiral Point, Stable Star, Unstable Improper Node, Unstable Node, Unstable Star

References

Tabor, M. ``Classification of Fixed Points.'' §1.4.b in Chaos and Integrability in Nonlinear Dynamics: An Introduction. New York: Wiley, pp. 22-25, 1989.