====== TTP03-19 Lectures on multiloop calculations ======
 
 
   <hidden TTP03-19  Lectures on multiloop calculations > I discuss methods of calculation of propagator diagrams
 (massless, those of Heavy Quark Effective Theory, and massive on-shell diagrams)
 up to 3 loops.
 Integration-by-parts recurrence relations are used to reduce them
 to linear combinations of basis integrals.
 Non-trivial basis integrals have to be calculated by some other method,
 e.g., using Gegenbauer polynomial technique.
 Many of them are expressed via hypergeometric functions;
 in the massless and HQET cases, their indices tend to integers
 at $\varepsilon\to0$.
 I discuss the algorithm of their expansion in $\varepsilon$,
 in terms of multiple $\zeta$ values.
 These lectures were given at Calc-03 school, Dubna, 14--20 June 2003.
 </hidden>
|**A. G. Grozin**  | 
|**  Int.J.Mod.Phys.  A19 473-520 2004  **  |
| {{preprints:2003:ttp03-19.pdf|PDF}} {{preprints:2003:ttp03-19.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0307297|arXiv]]   |
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