Symmetries of post-Galilean expansions

Understand

In this letter we study an infinite extension of the Galilei symmetry group in any dimension that can be thought of as a non-relativistic or post-Galilean expansion of the Poincare symmetry.

• We find an infinite-dimensional vector space on which this generalized Galilei group acts and usual Minkowski space can be modeled by our construction.
• We also construct particle and string actions that are invariant under these transformations.