Chaplygin gas with field-dependent Poincare symmetry

The relativistic generalization of the Chaplygin gas, put forward by Jackiw and Polychronakos, is derived in Duval’s Kaluza-Klein framework, using a universal quadratic Lagrangian. Our framework yields a simplified proof of the field-dependent Poincar'e symmetry Our action is related to the usual Nambu-Goto action [world volume] of $d$-branes in the same way as the Polyakov and the Nambu action are in strings theory.