Grassmannians and non-planar graphs

I will start with an overview of the connection between scattering amplitudes, non-negative Grassmannian and on-shell diagrams (plabic graphs). I will show how the non-planar plabic graphs naturally appear and physics and how the explicit results for scattering amplitudes can associate them with subspaces in the Grassmannian G(k,n). In the talk I mostly focus on the G(3,6) case which corresponds to a particular six-gluon amplitude on the physics side.