Perturbative Heavy Quark Fragmentation Function through O(α_s²): Gluon Initiated Contribution

We derive the gluon initiated contribution to the initial condition for the perturbative fragmentation function of a heavy quark through order O(\alpha_s^2) in the MS-bar scheme. This result is needed for the resummation with next-to-next-to-leading logarithmic accuracy of quasi-collinear logarithms ln^k(m^2) in heavy quark differential distributions by solving the complete DGLAP equation. Together with the previously evaluated fermion initiated components, this result completes the derivation of the initial condition for the perturbative fragmentation function at next-to-next-to-leading order.