A scale of critical exponents for semilinear waves with time-dependent damping and mass terms

This scale of critical exponents is consistent with the diffusion phenomenon, that is, it is the same scale of critical exponents of the Cauchy problem for the corresponding diffusive equation −Δv+b(t)vt+m2(t)v=|v|p,t≥0,x∈Rn,v(0,x)=φ(x).