Symplectic integrators for the matrix Hill's equation and its applications to engineering models
This work provides more accurate and efficient numerical methods for engineers and physicists modeling systems with parametric resonances, such as those described by Hill's equation.
The authors developed new sixth- and eighth-order symplectic exponential integrators for the matrix Hill's equation that preserve the symplectic structure, achieving accurate results for oscillatory problems at low computational cost.
We consider the numerical integration of the matrix Hill's equation. Parametric resonances can appear and this property is of great interest in many different physical applications. Usually, the Hill's equations originate from a Hamiltonian function and the fundamental matrix solution is a symplectic matrix. This is a very important property to be preserved by the numerical integrators. In this work we present new sixth-and eighth-order symplectic exponential integrators that are tailored to the Hill's equation. The methods are based on an efficient symplectic approximation to the exponential of high dimensional coupled autonomous harmonic oscillators and yield accurate results for oscillatory problems at a low computational cost. Several numerical examples illustrate the performance of the new methods.