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Precise numerical evaluation of the two loop sunrise graph Master Integrals in the equal mass case

S. Pozzorini·E. Remiddi
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Abstract

We present a double precision routine in Fortran for the precise and fast numerical evaluation of the two Master Integrals (MIs) of the equal mass two-loop sunrise graph for arbitrary momentum transfer in d=2 and d=4 dimensions. The routine implements the accelerated power series expansions obtained by solving the corresponding differential equations for the MIs at their singular points. With a maximum of 22 terms for the worst case expansion a relative precision of better than a part in 10^{15} is achieved for arbitrary real values of the momentum transfer.

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S. Pozzorini, E. Remiddi. 2005-05-06. Precise numerical evaluation of the two loop sunrise graph Master Integrals in the equal mass case. https://doi.org/10.1016/j.cpc.2006.05.005

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