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# Tag Archives: generalized line graphs

## 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
2 Comments

## The ADE affair, 1

In the 1970s, the American Mathematical Society held a symposium on Mathematical developments arising from Hilbert problems. Each of Hilbert’s problems was described, and subsequent progress and developments traced, by at least one expert in the area. As part of … Continue reading

Posted in exposition, history
Tagged Coxeter diagrams, Dynkin diagrams, generalized line graphs, Hilbert problems, root systems
1 Comment