  Antenna functions describe the infrared singular behaviour of colour-ordered
QCD matrix elements due to the emission of unresolved partons inside an antenna
formed by two hard partons. In this paper, we show that antenna functions for
hard gluon-gluon pairs can be systematically derived from the effective
Lagrangian describing Higgs boson decay into gluons, and compute the the
infrared structure of the colour-ordered Higgs boson decay matrix elements at
NLO and NNLO.
