In-person Math Counts May 2025 - Groups and their graphs

This will be a gentle introduction to abstract group theory, using the symmetries of the equilateral triangle. No text needed, I will introduce the formal definition of group action, and revisit the symmetric group S_3 as acting on the equilateral triangle, and explore the inner structure of S_3 -- subgroups and cosets. If there's enough time an introduction to orbits and stabilizers. Very spacy!

Time: 12:00 pm noon, Saturday February 8th, 2025.

Location: The food court at Liberty Place, 16th and Chestnut Street, Philadelphia, PA.

The far side of the food court where there are windows overlooking 17th Street tends to be less crowded than the main central area.