Asymptotic behavior of the generalized Korteweg-de Vries-Burgers equation

Cauchy's problem for a generalization of the KdV-Burgers equation is considered in Sobolev spaces H-1(R) and H-2(R). We study its local and global solvability and the asymptotic behavior of solutions (in terms of the global attractors). The parabolic regularization technique is used in this paper which allows us to extend the strong regularity properties and estimates of solutions of the fourth order parabolic approximations onto their third order limit-the generalized Korteweg-de Vries-Burgers (KdVB) equation. For initial data in H-2(R) we study the notion of viscosity solutions to KdVB, while for the larger H-1(R) phase space we introduce weak solutions to that problem. Finally, thanks to our general assumptions on the nonlinear term f guaranteeing that the global attractor is usually nontrivial (i.e., not reduced to a single stationary solution), we study an upper semicontinuity property of the family of global attractors corresponding to parabolic regularizations when the regularization parameter epsilon tends to 0(+) (which corresponds the passage to the KdVB equation).