Oscillation for a class of diffusive hematopoiesis model with several arguments

By considering solution curve’s or surface’s composition of the functions of several variables and constructing the suitable lower-upper solution pair for the following special diffusive Hematopoiesis model (0.1) $\frac{{\partial P(t,x)}} {{\partial t}} = \Delta P(t,x) - \gamma P(t,x) + \sum\limits_{i = 1}^m {\frac{{\beta _i P(t - \tau _i ,x)}} {{1 + P^n (t - \tau _i ,x)}}} $ under Neumann boundary condition, sufficient conditions are provided for the oscillation of the positive equilibrium for (0.1). Moreover, these results extend or complement existing results.