Multiple existence of periodic solutions for a nonlinear parabolic problem with singular nonlinearities Original Research Article

In this paper, we establish a multiple existence result of periodic solutions for a nonlinear parabolic equations with singular nonlinearity at zero. To establish our result, We use an approximating process by smooth nonlinear functions to avoid a singularity in nonlinear term. And we adapt topological argument based on the variational structure of functionals corresponding to approximating equations.