A semi-infinite matrix analysis of the BFKL equation N. Bethencourt de León, G. Chachamis, A. Romagnoni and A. Sabio Vera Eur. Phys. J. C, 80 6 (2020) 549 Published online: 17 June 2020 DOI: 10.1140/epjc/s10052-020-8098-0