The Britto–Cachazo–Feng–Witten recursion relations are a set of on-shell recursion relations in quantum field theory. They are named for their creators, Ruth Britto, Freddy Cachazo, Bo Feng and Edward Witten.
The BCFW recursion method is a way of calculating scattering amplitudes. Extensive use is now made of these techniques.
References
BCFW recursion Wikipedia(Text) CC BY-SA