Affine Kac–Moody algebras graded by affine root systems
Finite and Affine Reflection Groups
reference request - Definition of Affine Root System: What is $\alpha_{+}$? - MathOverflow
Affine Coxeter-Dynkin diagrams for the reduced, crystallographic root... | Download Scientific Diagram
Above: Three root systems and corresponding affine hyperplanes in R 2 .... | Download Scientific Diagram
Free Course: Symmetric closed subsets of real affine root systems and regular su.... (Short Talk) by Irfan Habib from International Centre for Theoretical Sciences | Class Central