%0 Journal Article %9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES %A Sanchez, E. %A Auger, Pierre %A Poggiale, J. C. %T Two-time scales in spatially structured models of population dynamics : a semigroup approach %D 2011 %L fdi:010053395 %G ENG %J Journal of Mathematical Analysis and Applications %@ 0022-247X %K Aggregation of variables ; Two-time scales ; Spatially structured ; population dynamics ; Reaction-diffusion equations %M ISI:000284293600013 %N 1 %P 149-165 %R 10.1016/j.jmaa.2010.08.014 %U https://www.documentation.ird.fr/hor/fdi:010053395 %> https://www.documentation.ird.fr/intranet/publi/2011/03/010053395.pdf %V 375 %W Horizon (IRD) %X The aim of this work is to provide a unified approach to the treatment of a class of spatially structured population dynamics models whose evolution processes occur at two different time scales. In the setting of the C-0-semigroup theory, we will consider a general formulation of some semilinear evolution problems defined on a Banach space in which the two-time scales are represented by a parameter epsilon > 0 small enough, that mathematically gives rise to a singular perturbation problem. Applying the so-called aggregation of variables method, a simplified model called the aggregated model is constructed. A nontrivial mathematical task consists of comparing the asymptotic behaviour of solutions to both problems when epsilon -> 0(+), under the assumption that the aggregated model has a compact attractor. Applications of the method to a class of two-time reaction-diffusion models of spatially structured population dynamics and to models with discrete spatial structure are given. %$ 020