"What I cannot create, I do not understand" - written on the blackboard of Richard Feynman at the time of his death.
We are a group which meets recreationally to re-create and understand the quantum theory from first principles. A prior knowledge of quantum mechanics is not necessary, but helpful. What is required, however, is a keen desire to learn - with the help of like-minded people - how Nature really operates on the fundamental, microscopic level. Oh...also, an ability to have fun doing so!
The 7th session of Sidd's series on representations of Lie groups and Lie algebras will focus on roots, weights, and Cartan matrices. Tensor products if time permits. See https://en.wikipedia.org/wiki/Root_system