A fixed point for which the stability matrix has eigenvalues of
the form 
(with 
).
Unstable Spiral Point
See also
Elliptic Fixed Point, Fixed Point, Hyperbolic Fixed Point, Stable Improper Node, Stable Node, Stable Spiral Point, Stable Star, Unstable Improper Node, Unstable Node, Unstable StarExplore with Wolfram|Alpha
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.Referenced on Wolfram|Alpha
Unstable Spiral PointCite this as:
Weisstein, Eric W. "Unstable Spiral Point." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/UnstableSpiralPoint.html