“…A natural generalization of the Jacobi-Davidson method for linear eigenproblems which was already suggested in [92,95] for polynomial eigenvalue problems and which was studied in [15,110] for general nonlinear eigenproblems is the following one: Suppose that the columns of V ⊂ C n form an orthonormal basis of the current search space, and let (x, θ) be a Ritz pair of (1) with respect to V , i.e. V H F (θ)V y = 0, x = V y.…”