Reduced measures associated to parabolic problems

We study the existence and the properties of the reduced measures for the parabolic equations $\partial_tu-\Delta u+g(u)=0$ in $\Omega\times (0,\infty)$ subject to the conditions ($P$): $u=0$ on $\partial\Omega\times (0,\infty)$, $u(x,0)=\mu$ and ($P'$): $u=\mu'$ on $\partial\Omega\times (0,\infty)$, $u(x,0)=0$ where $\mu$ and $\mu'$ are positive Radon measures and $g$ a continuous nondecreasing function