Master integrals for e+e− → 2γ process at large energies and angles

A bstract We calculate master integrals for the two-loop QED corrections to e + e − → 2 γ in terms of generalized power series with respect to electron mass. The coefficients of this series are expressed via Goncharov’s polylogarithms. Our approach exploits a number of modern multiloop methods: IBP reduction, differential equations for master integrals, Frobenius method, reduction to ϵ -form, and DRA method.