Applications of intersection numbers in physics

Abstract: In this review I discuss intersection numbers of twisted cocycles and their relation to physics. After defining what these intersection number are, I will first discuss a method for computing them. This is followed by three examples where intersection numbers appear in physics. These examples are: tree-level scattering amplitudes within the the CHY-formalism, reduction of Feynman integrals to master integrals and correlation functions on the lattice.