出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present a brief status report on calculations for the four-loop splitting functions in perturbative QCD, which will pave the way to future determination of N$^3$LO parton distribution functions of hadrons. In the large-$N_c$ limit, the exact four-loop contribution to the flavour non-singlet splitting functions has been obtained. For the remaining large-$N_c$ suppressed terms, we provide approximate expressions that are sufficient for phenomenological applications.
