Notes on 8 Majorana Fermions
Eight Majorana fermions in d=1+1d=1+1
dimensions enjoy a triality that permutes the representation of the
SO(8)SO(8)
global symmetry in which the fermions transform. This triality plays an
important role in the quantization of the superstring, and in the
analysis of interacting topological insulators and the associated
phenomenon of symmetric mass generation. The purpose of these notes is
to provide an introduction to the triality and its applications, with
careful attention paid to various
{\bf Z}_2
global and gauge symmetries and their coupling to background spin
structures.