Free Massless Particles, Two Time Physics and Newtonian Gravitodynamics
  We demonstrate how a classical Snyder-like phase space can be constructed in the Hamiltonian formalism for the free massless relativistic particle, for the two-time physics model and for the relativistic Newtonian gravitodynamic theory. In all these theories the Snyder-like phase space emerges as a consequence of a new local scale invariance of the Hamiltonian. The implications and consequences of this Snyder-like phase space in each of these theories are also considered. 
W. Chagas-Filho