Morphisms fixing words associated with exchange of three intervals
  We consider words coding exchange of three intervals with permutation (3,2,1), here called 3iet words. Recently, a characterization of substitution invariant 3iet words was provided. We study the opposite question: what are the morphisms fixing a 3iet word? We reveal a narrow connection of such morphisms and morphisms fixing Sturmian words using the new notion of amicability. 
Petr Ambro\v{z}, Zuzana Mas\'akov\'a, Edita Pelantov\'a