Numerical evaluation of master integrals from differential equations
  The 4-th order Runge-Kutta method in the complex plane is proposed for numerically advancing the solutions of a system of first order differential equations in one external invariant satisfied by the master integrals related to a Feynman graph. The particular case of the general massive 2-loop sunrise self-mass diagram is analyzed. The method offers a reliable and robust approach to the direct and precise numerical evaluation of master integrals. 
M. Caffo (1 and 2), H. Czyz (3) and E. Remiddi (2 and 1) ((1)   INFN-Bologna, (2) Univ. of Bologna, (3) Univ. of Silesia)