Fronts with a growth cutoff but with speed higher than the linear spreading speed
نویسندگان
چکیده
منابع مشابه
Fronts with a growth cutoff but with speed higher than the linear spreading speed.
Fronts, propagating into an unstable state phi=0, whose asymptotic speed v(as) is equal to the linear spreading speed v* of infinitesimal perturbations about that state (so-called pulled fronts), are very sensitive to changes in the growth rate f(phi) for phi<<1. It was recently found that with a small cutoff, f(phi)=0 for phi< epsilon, v(as) converges to v* very slowly from below, as ln(-2) ep...
متن کاملSpeed 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 mak...
متن کاملFunctional Speed Reserve as a Proxy for the Anaerobic Speed Reserve Using the Critical Speed Concept
Background: Although maximal sprint speed (MSS) and the anaerobic speed reserve (ASR) provides valuable information about the speed profile of athletes, these parameters fall short of providing important information about sub-maximal metabolic thresholds. The only field test that can offer an estimate of a sub-maximal metabolic threshold is the 3-minute all-out test for running (3MT) which deli...
متن کاملSpreading speed and linear determinacy for two-species competition models.
One crucial measure of a species' invasiveness is the rate at which it spreads into a competitor's environment. A heuristic spread rate formula for a spatially explicit, two-species competition model relies on 'linear determinacy' which equates spread rate in the full nonlinear model with spread rate in the system linearized about the leading edge of the invasion. However, linear determinacy is...
متن کاملPossibility of a Light Pulse with Speed Greater than c
In two models it is shown that a light pulse propagates from a vacuum into certain media with velocity greater than that of a light in a vacuum (c). By numerical calculation the propagating properties of such a light are given. Recently L. J. Wang and his collaborators in their experiment [1] have found that the group velocity of a laser pulse in particularly prepared atomic caesium gas can muc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review E
سال: 2002
ISSN: 1063-651X,1095-3787
DOI: 10.1103/physreve.66.015206