Conserved Quantities and the Algebra of Braid Excitations in Quantum   Gravity
  We derive conservation laws from interactions of braid-like excitations of embedded framed spin networks in Quantum Gravity. We also demonstrate that the set of stable braid-like excitations form a noncommutative algebra under braid interaction, in which the set of actively-interacting braids is a subalgebra. 
Song He, Yidun Wan