A fixed point for which the eigenvalues are complex conjugates.
Spiral Point
See also
Stable Spiral Point, Unstable Spiral PointExplore 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
Spiral PointCite this as:
Weisstein, Eric W. "Spiral Point." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SpiralPoint.html