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Branwen Purdy at her stall during OMSI meet-a-scientist day.

Branwen Purdy prepares hands-on activities for kids at the OMSI Meet-A-Scientist Day in Portland, to share hands-on learning experiences about her research in topological data analysis.

Join us for these events hosted by the Department of Mathematics, including colloquia, seminars, graduate student defenses and outreach, or of interest to Mathematicians hosted by other groups on campus.

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Complex simple lie algebras: (de)classified

STAG 112
Graduate Student Seminar

Speaker: Addison Day

A Lie algebra in its most concrete form is the tangent space at the identity element of a Lie group. Using basic ideas from differential geometry, one can show that centerless, simple, compact Lie groups are determined by their Lie algebras, and vice versa. These Lie algebras in turn correspond to irreducible Euclidean root systems - certain rigid subsets of Euclidean space. One can then show that irreducible Euclidean root systems correspond to connected Dynkin diagrams, whose classification is an elementary problem in Euclidean geometry. Tracing these bijections in reverse, one lands at a classification of centerless, simple, compact Lie groups, and their associated Lie algebras. In this talk we will discuss the above process in more detail, focusing primarily on the association of a complex, simple, finite dimensional Lie algebra, to an irreducible Euclidean root system. We will also briefly discuss some connections to representation theory and knot theory. Read more.