Spin network
A
spin network is a
graph whose edges are associated with
representations of a
Lie group, G and
vertices are associated with intertwiners of the edge reps adjacent to it. It was invented by
Roger Penrose in
1971. Spin networks were applied to the
physics problem of
quantum gravity by
Lee Smolin,
Fotini Markopoulou-Kalamara, and others to reformulate
loop quantum gravity and
gauge theory.