“…Note that if p(ρ) = Cρ q , ρ ≥ 0, C > 0, q ≥ 1, then, the fluid is called isentropic and isothermal when q > 1 and q = 1, respectively. For other possibilities of the pressure function, readers may refer to [5] and the references therein. Cauchy problem with bounded measurable initial data for (1.1):…”