Interactions of reggeized gluons in the Möbius representation Original Research Article

We investigate consequences of the Möbius invariance of the BFKL Hamiltonian and of the triple Pomeron vertex. In particular, we show that the triple Pomeron vertex in QCD, when restricted to the large image limit and to the space of Möbius functions, simplifies and reduces to the vertex used in the Balitsky–Kovchegov (BK) equation. As a result, the BK equation for the dipole density appears as a special case of the non-linear evolution equation which sums the fan diagrams for BFKL Greenʹs functions in the Möbius representation. We also calculate the corrections image to the triple Pomeron vertex in the space of Möbius functions, and we present a generalization of the BK equation in the next-to-leading order approximation in the image expansion.