Abstract:
Given a degenerate parabolic equation of the form
$\rho(x) u_t=\operatorname{div}(u^{m-1}|Du|^{\lambda-1}Du)+\rho(x)u^p$
with a source and inhomogeneous density,
we consider the Cauchy problem with an initial function slowly tending to zero
as $|x| \to \infty$. We find conditions for the global-in-time existence or
non-existence of solutions of this problem. These conditions depend
essentially on the behaviour of the initial data as $|x|\to \infty$.
In the case of global solubility we obtain a sharp estimate of the solution
for large values of time.