Dynamics of Spin Networks

This chapter covers the dynamics of quantum spacetime, utilising networks labelled with spin representations to describe kinematical states, and exploring how these spin networks evolve between initial and final states through a sum-over-geometries (so-called ‘spin foams’). The historical development of these ideas is described. BF theory, the role of a cosmological constant in taming infinities, and the connection to Chern–Simons theory are discussed. In addition, several modern developments, such as the analysis of dynamics through coherent states, and group field theor, are introduced.