Towards $gg\to HH$ at next-to-next-to-leading order: light-fermionic three-loop corrections

Joshua Davies, Kay Schönwald, Matthias Steinhauser

We consider light-fermion three-loop corrections to $gg\to HH$ using forward scattering kinematics in the limit of a vanishing Higgs boson mass, which covers a large part of the ph…