Floquet multiplier

Summary

The Floquet multipliers of a linear system with periodic coefficients are the eigenvalues of its monodromy matrix, the map that advances solutions by one period. They play the role that the values $e^{\lambda T}$ play for a system with constant coefficients. They decide whether solutions grow, decay or stay bounded, and they measure the stability of a periodic orbit of a nonlinear system. They are the central notion of Floquet theory. See the definition.