Long-time dynamics of fractional nonclassical diffusion equations with nonlinear colored noise and delay on unbounded domains

This paper deals with the long-time dynamics for a class of highly nonlinear fractional nonclassical diffusion equations with nonlinear colored noise and time delay defined on the whole space R-n. The existence and uniqueness of tempered pullback random attractors of the equations are established in C([-rho, 0], H-alpha(R-n))(rho > 0 and alpha is an element of (0, 1)) for polynomial growth drift and diffusion terms as well as Lipschitz time-delay terms. In a special case where the nonlinear diffusion term depends only on the space variable, the approximation of those random attractors is also investigated in C([-rho, 0], H-alpha(R-n)) when the correlation time of the colored approaches zero. The pullback asymptotical compactness of the solutions in C([-rho, 0], H-alpha(R-n)) is proved by virtue of the arguments of Arzela-Ascoli theorem, spectral decomposition as well as uniform tail-estimates developed by Wang (1999) [59] in order to surmount several difficulties caused by the lack of compact Sobolev embeddings on unbounded domains as well as the weakly dissipative distinguishing structures of the equations. (c) 2021 Elsevier Masson SAS. All rights reserved.