Pullback and uniform attractors for nonautonomous reaction-diffusion equation in Dumbbell domains

This work is devoted to the study of the asymptotic behavior of nonautonomous reaction-diffusion equations in Dumbbell domains $\Omega_{\varepsilon} \subset $\mathbb{R}$^{N}$\mathrm{.}Each$\Omega_{\varepsilon}$istheunionofafixedopenset$\Omega$andachannel$R_{\varepsilon}$thatcollapsestoalinesegment$R_0$as$\varepsilon \rightarrow 0^{+}$. We first establish the global existence of solution for each problem by using two properties of the parabolic equation considered, which are the positivity of the solutions and comparison results for them. We prove the existence of pullback and uniform attractors and we obtain uniform bounds (in $\epsilon$) for them.