Pulsating Semi-waves in Periodic Media and Spreading Speed Determined by a Free Boundary Model
نویسنده
چکیده
We consider a radially symmetric free boundary problem with logistic nonlinear term. The spatial environment is assumed to be asymptotically periodic at infinity in the radial direction. For such a free boundary problem, it is known from [7] that a spreading-vanishing dichotomy holds. However, when spreading occurs, only upper and lower bounds are obtained in [7] for the asymptotic spreading speed. In this paper, we investigate one dimensional pulsating semi-waves in spatially periodic media. We prove existence, uniqueness of such pulsating semiwaves, and show that the asymptotic spreading speed of the free boundary problem coincides with the speed of the corresponding pulsating semi-wave.
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