4 research outputs found
Lattices of topologies of algebraic systems
The article is based on the report, which was
delivered on a plenary sitting on the 5th International Algebraic
Conference in the Ukraine (Odessa, July, 2005) and is a survey
of the results on the lattices of topologies of different algebraic
systems
Sums over Graphs and Integration over Discrete Groupoids
We show that sums over graphs such as appear in the theory of Feynman
diagrams can be seen as integrals over discrete groupoids. From this point of
view, basic combinatorial formulas of the theory of Feynman diagrams can be
interpreted as pull-back or push-forward formulas for integrals over suitable
groupoids.Comment: 27 pages, 4 eps figures; LaTeX2e; uses Xy-Pic. Some ambiguities
fixed, and several proofs simplifie