Abstract
Structure-preserving two-step linearly implicit exponential integrators
are constructed for Hamiltonian partial differential equations with
linear constant damping combining exponential integrators and
polarization of the polynomial Hamiltonian function. We also construct
an exponential version of the well-known one-step Kahan’s method by
polarizing the quadratic vector field. These integrators are applied to
one-dimensional damped Burger’s, Korteweg-de Vries, and nonlinear
Schrödinger equations. Preservation of the dissipation rate is
demonstrated for linear, quadratic conformal invariants and of the
Hamiltonians by numerical experiments.