Two-Loop Gluon Regge Trajectory from Lipatov's Effective Action
  Lipatov's high-energy effective action is a useful tool for computations in the Regge limit beyond leading order. Recently, a regularisation/subtraction prescription has been proposed that allows to apply this formalism to calculate next-to-leading order corrections in a consistent way. We illustrate this procedure with the computation of the gluon Regge trajectory at two loops. 
Grigorios Chachamis, Martin Hentschinski, Jos\'e Daniel Madrigal and   Agust\'in Sabio Vera
hep-ph