Pseudopalindromes

A generalized palindromization map in free monoids

The palindromization map $\psi$ in a free monoid $A^{\*}$ was introduced in 1997 by the first author in the case of a binary alphabet $A$, and later extended by other authors to arbitrary alphabets. Acting on infinite words, $\psi$ generates the …

Characteristic morphisms of generalized episturmian words

In a recent paper with L. Q. Zamboni, the authors introduced the class of *$\vartheta$-episturmian* words. An infinite word over $A$ is standard $\vartheta$-episturmian, where $\vartheta$ is an involutory antimorphism of $A^{\*}$, if its set of …

On $\theta$-episturmian words

In this paper we study a class of infinite words on a finite alphabet $A$ whose factors are closed under the image of an involutory antimorphism $\theta$ of the free monoid $A^\*$. We show that given a recurrent infinite word $\omega \in …

On some problems related to palindrome closure

In this paper we solve some open problems related to (pseudo)palindrome closure operators and to the infinite words generated by their iteration, that is, standard episturmian and pseudostandard words. We show that if $\vartheta$ is an …

On a Generalization of Standard Episturmian Morphisms

In a recent paper with L. Q. Zamboni the authors introduced the class of *$\vartheta$-episturmian* words, where $\vartheta$ is an involutory antimorphism of the free monoid $A^{*}$. In this paper, we introduce and study …

Combinatorial aspects of Sturmian sequences and their generalizations

On different generalizations of episturmian words

In this paper we study some classes of infinite words generalizing episturmian words, and analyse the relations occurring among such classes. In each case, the reversal operator $R$ is replaced by an arbitrary involutory antimorphism $\vartheta$ …

Pseudopalindrome closure operators in free monoids

We consider involutory antimorphisms $\vartheta$ of a free monoid $A^{\*}$ and their fixed points, called $\vartheta$-palindromes or pseudopalindromes. A $\vartheta$-palindrome reduces to a usual palindrome when $\vartheta$ is the reversal …