2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45779Using reggeon diagrams as a partial implementation of $t$-channel unitarity, $O(g^4)$ corrections to the BFKL evolution equation have been obtained. We describe the spectrum and holomorphic factorization properties of the resulting scale-invariant kernel. For a gauge theory, $t$-channel unitarity can be studied directly in the complex $j$-plane by implementing Ward identity constraints together with the group structure of reggeon interactions. We discuss how both the $O(g^2)$ BFKL kernel and the $O(g^4)$ corrections can then be derived.6 pages in latex, 2 ps fig. Presented at the VIth International Conference on Elastic and Diffractive Scattering ``Frontiers in Strong Interactions'', Blois, France (June 1995)High Energy Physics - PhenomenologyHigh Energy Physics - Theorytext