Resumen:
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We consider the Cauchy problem ut = ?(u)xx + ?(u), (t, x) ? R+ × R, u(0, x) = u0(x), x ? R, when the increasing function ? satisfies that ?(0) = 0 and the equation may degenerate at u = 0 (in the case of ?? (0) = 0). We consider the case of u0 ? L?(R), 0 u0(x) 1 a.e. x ? R and the special case of ?(u) = u ? ?(u). We prove that the solution approaches the travelling wave solution (with speed c = 1), spreading either to the right or to the left, or to the two travelling waves moving in opposite directions.
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