Observations on spacetime symmetry and non-commutativity
  We consider both the co-ordinates and momenta to be non-commutative and define a non-commutative version of Lorentz symmetry which has a smooth limit to the standard Lorentz symmetry. The Poincar\acute{e} algebra in this spacetime has also been discussed. 
Pulak Ranjan Giri, T. Shreecharan