The Explicit Closure for the Ultrarelativistic Limit of Extended Thermodynamics of Rarefied Polyatomic Gas

In a recent paper the ultra-relativistic limit of a recent theory proposed by Pennisiand Ruggeri for polyatomic relativistic gas has been considered. This was importantto check the general article. In particular, the explicitly expression of the characteristicvelocities of the hyperbolic system were found for every value of the parameter ameasuring ”how much” the gas is polyatomic. This result was achieved in terms of thecomponents of the main field as independent variables and without writing it in termsof the physical variables. Here the closure of the field equations is considered in termsof these physical variables and their ultrarelatistic limit is obtained