2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/146970We study the asymptotic behavior of nonnegative solutions of the semilinear parabolic problem {u_t=Δu + u^{p}, x\in\mathbb{R}^{N}, t>0 u(0)=u_{0}, x\in\mathbb{R}^{N}, t=0. It is known that the nonnegative solution $u(t)$ of this problem blows up in finite time for $1<p\leq 1+ 2/N$. Moreover, if $p> 1+ 2/N$ and the norm of $u_{0}$ is small enough, the problem admits global solution. In this work, we use the entropy method to obtain the decay rate of the global solution $u(t)$.15Analysis of PDEs35B40; 35B35; 35K65; 35K55text