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Tag Archives: line graph
Butterflies
I am in Lisbon working with João Araújo and Wolfram Bentz on synchronization. We say that a permutation group G on the set {1,…n} synchronizes a non-permutation f from this set to itself if the semigroup generated by G and … Continue reading
The ADE affair, 5
A root system is a finite set S of vectors in Euclidean space with the properties If s,λs∈S, then λ=±1. The set S is mapped to itself by the reflection in the hyperplane perpendicular to each element s of S. … Continue reading
Posted in exposition
Tagged Coxeter group, generalized line graphs, line graph, root systems, Whitney's theorem
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