Light Propagation in an Expanding Universe

Abstract

Following the rapid development of cosmological theory after 1930, H.G. Robertson and A.G. Walker proposed independently in 1935 a General Relativistic type metric which incorporates the basic assumptions of -

• I universal structure in terms of an homogeneous ensemble of fundamental particles;

• II the universal operation of a Cosmological Principle;

• III the expansion of the whole system according to Hubble’s Law.