Formation and damping of relativistic strong shocks in a Synge gas

Results are presented from a detailed study of the formation and subsequent damping of strong relativistic shocks in a fluid obeying the Synge equation of state for a relativistic particle gas. The study is confined to planar one-dimensional flow within the flat space-time of special relativity. The simple wave relations are derived and compared with corresponding shock solutions. A detailed comparison of the Synge gas and a photon-dominated gas is given. It is shown that for a given velocity gradient, the compression ratio is higher for the photon-dominated gas than for the Synge gas, whereas the temperature and the internal energy are increased by more in the Synge gas. The photon-dominated gas also produces more entropy than the Synge gas. The results may be pertinent to the study of supernovae, extragalactic radio sources, and pregalactic fluctuations.