Critical exponent for nonlinear wave equations with frictional and   viscoelastic damping terms
  In this paper, we study the Cauchy problem for a nonlinear wave equation with frictional and viscoelastic damping terms. Our aim is to obtain the threshold, to classify the global existence of solution for small data or the finite time blow-up pf the solution, with respect to the growth order of the nonlinearity. 
Ryo Ikehata and Hiroshi Takeda
math.AP