Algebra Seminar: Graham -- Some Reflections on Root Systems

John Graham 

Friday 23 February, 12-1pm, Place: Carslaw 375 

Title: Some Reflections on Root Systems.  

Abstract: Crystallographic finite and affine root systems are normally studied for their
applications to Lie theory.  To entertain myself while I was learning some programming,
I built a module to calculate with them following Bourbaki and Macdonald.  In the talk I
present some observations from this perspective that don't seem to have made it to the
textbooks.  The themes are (1) concrete constructions; (2) the ignored non-reduced case;
and (3) folding and twisting.