Scattering Amplitudes, the AdS/CFT Correspondence, Minimal Surfaces, and Integrability
Figure 8
When looking at the left problem, (each sheet of) the -plane is naturally divided into two parts, according to the sign of . In the same way, when looking at the right problem, the -plane is naturally divided into two parts, according to the sign of . Hence, the -plane is naturally divided into four quadrants. Large values of in each of these angular sectors correspond to a cusp.
