In cosmological special relativity theory, we study Maxwell equations, electromagnetic wave equations and functions. In the cosmological special theory of relativity, we study energymomentum relations, the Klein-Gordon equation and wave functions. If we solve the KleinGordon equation, we obtain the Yukawa potential in the cosmological inertial frame. We derive the Schrodinger equation from Klein-Gordon free particle’s wave function in the cosmological special theory of relativity. We derive the uncertainty principle in cosmological quantum mechanics in cosmological special relativity theory. The Dirac equation is a one order wave equation. The wave function is used as a probability amplitude in quantum mechanics. We derive the Dirac equatio...