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![Wolfram Library Archive](/images/database/subheader.gif)
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![](/common/images/spacer.gif) SOME REMARKS ON NON-PLANAR FEYNMAN DIAGRAMS
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Organization: | Institute of Physics, University of Silesia |
Organization: | Institute of Physics, University of Silesia |
Organization: | Institute of Physics, University of Silesia |
Organization: | Deutsches Elektronen-Synchrotron, DESY |
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![](/common/images/spacer.gif) Two criteria for planarity of a Feynman diagram upon its propagators (momentum flows) are presented. Instructive Mathematica programs that solve the problem and examples are provided. A simple geometric argument is used to show that while one can planarize non-planar graphs by embedding them on higher-genus surfaces (in the example it is a torus), there is still a problem with defining appropriate dual variables since the corresponding faces of the graph are absorbed by torus generators.
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