Title: Quenching of stable pulses in slow-fast excitable media

Abstract: We develop linear theory for the prediction of excitation wave quenching--the construction of minimal perturbations which return stable excitations to quiescence--for localized pulse solutions of models of excitable media. The theory requires accounting for an additional degree of freedom in the formulation of the linear theory, and a reconsideration of heuristics for choosing optimal reference states from their group representation. We compare the predictions made with the linear theory to direct numerical simulations across a family of perturbations and assess the accuracy of predictions for models with distinct stable excitation structures. We find that the theory achieves qualitative predictive power with only the effort of distinguishing a root from the asymptotic case, and achieves quantitative predictive power in many circumstances. Finally, we compare the computational cost of our prediction technique to other numerical methods for the determination of transitions in extended excitable systems.