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Some Remarks on Non-Planar Diagrams

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 نشر من قبل Gluza Janusz Dr
 تاريخ النشر 2013
  مجال البحث
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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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