NONLINEAR DIFFUSION PROBLEMS WITH FREE BOUNDARIES: CONVERGENCE, TRANSITION SPEED, AND ZERO NUMBER ARGUMENTS.
In: SIAM Journal on Mathematical Analysis, Jg. 47 (2015-09-01), Heft 5, S. 3555-3584
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Zugriff:
This paper continues the investigation of [Du and Lou, J. Eur. Math. Soc. (JEMS), arXiv:1301.5373, 2013], where the long-time behavior of positive solutions to a nonlinear diffusion equation of the form ut = uxx + f(u) for x over a varying interval (g(t), h(t)) was examined. Here x = g(t) and x = h(t) are free boundaries evolving according to g'(t) = −μux(t, g(t)), h'(t) = −μux(t, h(t)), and u(t, g(t)) = u(t, h(t)) = 0. We answer several intriguing questions left open in that investigation. First we prove the conjectured convergence result for the general case that f is C1 and f(0) = 0. Second, for bistable and combustion types of f, we determine the asymptotic propagation speed of h(t) and g(t) in the transition case. More presicely, we show that when the transition case happens, for bistable type of f there exists a uniquely determined c1 > 0 such that limt→∞h(t)/ ln t = limt→∞−g(t)/ ln t = c1, and for combustion type of f, there exists a uniquely determined c2 > 0 such that limt→∞ h(t)/ √ t = limt→∞−g(t)/ √ t = c2. Our approach is based on the zero number arguments of Matano and Angenent and on the construction of delicate upper and lower solutions. [ABSTRACT FROM AUTHOR]
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NONLINEAR DIFFUSION PROBLEMS WITH FREE BOUNDARIES: CONVERGENCE, TRANSITION SPEED, AND ZERO NUMBER ARGUMENTS.
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Autor/in / Beteiligte Person: | YIHONG, DU ; BENDONG, LOU ; MAOLIN, ZHOU |
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Zeitschrift: | SIAM Journal on Mathematical Analysis, Jg. 47 (2015-09-01), Heft 5, S. 3555-3584 |
Veröffentlichung: | 2015 |
Medientyp: | academicJournal |
ISSN: | 0036-1410 (print) |
DOI: | 10.1137/140994848 |
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