We explain how Regge theory and perturbative evolution may be made compatible at small x. The result not only gives striking support to the two-pomeron description of small-x behaviour, but gives a rather clean test of perturbative QCD itself. When x is very small, the proton's gluon distribution function is significantly larger than is commonly believed. Perturbative evolution is invalid below Q2 ≈ 5 GeV2. © 2002 Elsevier Science B.V. All rights reserved.
Donnachie, A., & Landshoff, P. V. (2002). Perturbative QCD and Regge theory: Closing the circle. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 533(3–4), 277–284. https://doi.org/10.1016/S0370-2693(02)01556-3