Conservation Laws Invariant for Galileo Group; Cemracs Preliminary   results
  We propose a notion of hyperbolic system of conservation laws invariant for the Galileo group of transformations. We show that with natural physical and mathematical hypotheses, such a system conducts to the gas dynamics equations or to exotic systems that are detailed in this contribution to Cemracs 99. 
Fran\c{c}ois Dubois (LM-Orsay)
math-ph math.MP math.NA