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Question

Math 6410 • ODE

Fall 2017 • Question 4

  1. Let \(A(t)\) be a continuous, non-constant, real matrix-valued, \(T>0\) periodic function \(A(t+T)=A(t)\). For the system \[ \dot {x}=A(t)x \tag {4} \] define: Monodromy Matrix, Floquet Multipliers and Floquet Exponents.
  2. If \(e^{T\gamma }=\rho \) is a Floquet multiplier, then there is a solution of (4) of the form \[ x(t)=e^{\gamma t}p(t) \] where \(p(t)=\pm p(t+T)\).
  3. Prove that this equation does not have a fundamental set of bounded solutions. \[ \ddot {x}-(\cos ^2t)\dot {u}+(\sin ^2t)u=0 \]

Raw LaTeX

\begin{enumerate}
\item[(a)] Let \(A(t)\) be a continuous, non-constant, real matrix-valued, \(T>0\)
periodic function \(A(t+T)=A(t)\). For the system
\[
  \dot{x}=A(t)x
  \tag{4}
\]
define: \textit{Monodromy Matrix}, \textit{Floquet Multipliers} and
\textit{Floquet Exponents}.
\item[(b)] If \(e^{T\gamma}=\rho\) is a Floquet multiplier, then there is a solution
of (4) of the form
\[
  x(t)=e^{\gamma t}p(t)
\]
where \(p(t)=\pm p(t+T)\).
\item[(c)] Prove that this equation does not have a fundamental set of bounded
solutions.
\[
  \ddot{x}-(\cos^2t)\dot{u}+(\sin^2t)u=0
\]
\end{enumerate}