Palindromes and local periodicity
A. Blondin, A. Garon · 2009
In this paper we consider several types of equations on words, motivated by the attempt of characterizing the class of polyominoes that tile the pla ne by translation in two distinct ways. Words coding the boundary of these polyominoes satisfy an equation whose solutions are in bijection with a subset of the solutions of equations o f the form AB e A e B ≡ XY e X e Y . It turns out that the solutions are strongly related to local pe riodicity involving palindromes and conjugate words.