Density and Co-Density Results of Perturbed Evolutionary Hemivariational Inequality and Their Applications

We are mainly concerned with a perturbed hemivariational inequality involving time-dependent maximal monotone operators and history-dependent operators. First, we prove the existence results for the problem. Next, we establish the density and co-density results of the solution set. Finally, as an illustrative application, we study a frictional contact problem for viscoelastic materials.