Full paper in PDF:
$%J. Giacomoni, Some results about blow-up and global existence to a semilinear degenerate heat equation, Rev. Mat. Complut. 11 (1998), no. 2, 325351.%$

Some Results about Blow-Up and Global Existence to a Semilinear Degenerate Heat Equation
Jacques GIACOMONI
CEREMADE (URA.CNRS N 749)
Université de Paris-Dauphine
75775 Paris Cedex 16 France

Received: October 6, 1997
Revised: February 9, 1998
ABSTRACT

In this paper, we are dealing with the following degenerate parabolic problem:

   { @tu -|x|2Du = g(u) in R+ ×B1
(Pt)  u(t,x) =_  0 in R+ × @B1; u(0,x)= u > 0
                                  0

where B1 = {x  (- RN ;||x||= 1} and g  is nonlinear.

We are interested in analyzing such questions as local and global existence, blow-up in finite time and convergence to a stationary solution for solutions of (Pt)  .

First, we give some examples of nonlinearities g  where the blow up in L2(dx/|x|2) /~\  L oo (B1)  occurs. In a second part of this work, we present two cases of global existence of solutions to (Pt)  which converge in L oo (B1)  to a stationary solution of (Pt)  when t-->  oo  .

1991 Mathematics Subject Classification: 35K65.