Power law inflation and scalar field cosmology with a causal viscous fluid

This work investigates the nature of the potential function $V\left(\phi \right)$ relevant to power law inflation in a minimally coupled scalar field cosmology along with a perfect or causal viscous fluid. It is observed that if the coefficient of viscosity is proportional to the square root of the density of the fluid, the required potential is an exponential function of the scalar field φ.