Conformal kernel for NLO BFKL equation in ${\cal N}$=4 SYM
  Using the requirement of M\"{o}bius invariance of ${\cal N}$=4 SYM amplitudes in the Regge limit we restore the conformal NLO BFKL kernel out of the eigenvalues known from the forward NLO BFKL result. 
Ian Balitsky and Giovanni A. Chirilli