Reggeization of the amplitude of gluon-gluon scattering

In the two-loop approximation, the s-channel discontinuity of the amplitude of elastic gluon-gluon scattering with gluon quantum numbers and negative signature in the t-channel is calculated in the Regge kinematical region. Under the assumption that the asymptotic behavior of the amplitude in the Regge region is determined by the contribution of the reggeized gluon, the resulting discontinuity is used to calculate the gluon trajectory in the two-loop approximation. Agreement of the result with the two-loop correction to the trajectory as calculated from the amplitude of quark-quark scattering confirms gluon reggeization beyond the leading logarithmic approximation.