Speed of pulled fronts with a cutoff.
We study the effect of a small cutoff epsilon on the velocity of a pulled front in one dimension by means of a variational principle. We obtain a lower bound on the speed dependent on the cutoff, for which the two leading order terms correspond to the Brunet-Derrida expression. To do so we cast a known variational principle for the speed of propagation of fronts in different variables which makes it more suitable for applications.
Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago, Chile.
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Benguria
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MC
Depassier