Group Momentum Space and Hopf Algebra Symmetries of Point Particles Coupled to 2+1 Gravity
Group Momentum Space and Hopf Algebra Symmetries of Point Particles Coupled to 2+1 Gravity
We present an in-depth investigation of the ${\rm SL}(2,\mathbb{R})$ momentum space describing point particles coupled to Einstein gravity in three space-time dimensions. We introduce different sets of coordinates on the group manifold and discuss their properties under Lorentz transformations. In particular we show how a certain set of coordinates exhibits …