0000000000798083
AUTHOR
Ariel Sánchez
Asymptotic behavior for the heat equation in nonhomogeneous media with critical density
Abstract We study the long-time behavior of solutions to the heat equation in nonhomogeneous media with critical singular density | x | − 2 ∂ t u = Δ u , in R N × ( 0 , ∞ ) in dimensions N ≥ 3 . The asymptotic behavior proves to have some interesting and quite striking properties. We show that there are two completely different asymptotic profiles depending on whether the initial data u 0 vanishes at x = 0 or not. Moreover, in the former the results are true only for radially symmetric solutions, and we provide counterexamples to convergence to symmetric profiles in the general case.
Large time behavior for a porous medium equation in a nonhomogeneous medium with critical density
Abstract We study the large time behavior of solutions to the Cauchy problem for the porous medium equation in nonhomogeneous media with critical singular density | x | − 2 ∂ t u = Δ u m , in R N × ( 0 , ∞ ) , where m > 1 and N ≥ 3 , with nonnegative initial condition u ( x , 0 ) = u 0 ( x ) ≥ 0 . The asymptotic behavior proves to have some interesting and striking properties. We show that there are different asymptotic profiles for the solutions, depending on whether the continuous initial data u 0 vanishes at x = 0 or not. Moreover, when u 0 ( 0 ) = 0 , we show the convergence towards a peak-type profile presenting a jump discontinuity, coming from an interesting asymptotic simplification…