“…This can be used for the construction of numerical schemes which preserve positive pressure and satisfy a discrete version of the entropy inequality, see [10,11,13]. Some other analytical and numerical methods for the ultra relativistic Euler equations are studied in [1,2,3,8,12,15,16,17,18]. Recently numerical results using central upwind scheme are reported in [7] for one and two dimensional special ultra-relativistic Euler equations.…”