English

On the Zero Defect Conjecture

Combinatorics 2018-01-09 v2 Formal Languages and Automata Theory

Abstract

Brlek et al. conjectured in 2008 that any fixed point of a primitive morphism with finite palindromic defect is either periodic or its palindromic defect is zero. Bucci and Vaslet disproved this conjecture in 2012 by a counterexample over ternary alphabet. We prove that the conjecture is valid on binary alphabet. We also describe a class of morphisms over multiliteral alphabet for which the conjecture still holds. The proof is based on properties of extension graphs.

Keywords

Cite

@article{arxiv.1606.05525,
  title  = {On the Zero Defect Conjecture},
  author = {Sébastien Labbé and Edita Pelantová and Štěpán Starosta},
  journal= {arXiv preprint arXiv:1606.05525},
  year   = {2018}
}

Comments

v1: 16 pages, 3 figures; v2: 18 pages, 3 figures

R2 v1 2026-06-22T14:27:56.156Z