====== TTP03-36 The analytic value of a 4-loop sunrise graph in a particular kinematical configuration ====== The 4-loop sunrise graph with two massless lines, two lines of equal mass M and a line of mass m, for external invariant timelike and equal to m^2 is considered. We write differential equations in x=m/M for the Master Integrals of the problem, which we Laurent-expand in the regularizing continuous dimension $d$ around $d=4$, and then solve exactly in x up to order (d-4)^3 included; the result is expressed in terms of Harmonic PolyLogarithms of argument x and maximum weight 7. As a by product, we obtain the x=1 value, expected to be relevant in QED 4-loop static quantities like the electron (g-2). The analytic results were checked by an independent precise numerical calculation |**S. Laporta, P. Mastrolia and E. Remiddi** | |** Nucl. Phys. B 688 165-188 2004 ** | | {{preprints:2003:ttp03-36.pdf|PDF}} {{preprints:2003:ttp03-36.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0311255|arXiv]] | | |