{ "id": "math/0603608", "version": "v1", "published": "2006-03-26T13:31:56.000Z", "updated": "2006-03-26T13:31:56.000Z", "title": "Palindromic complexity of infinite words associated with simple Parry numbers", "authors": [ "Petr Ambrož", "Christiane Frougny", "Zuzana Masáková", "Edita Pelantová" ], "comment": "28 pages, to appear in Annales de l'Institut Fourier", "categories": [ "math.CO", "math.NT" ], "abstract": "A simple Parry number is a real number \\beta>1 such that the R\\'enyi expansion of 1 is finite, of the form d_\\beta(1)=t_1...t_m. We study the palindromic structure of infinite aperiodic words u_\\beta that are the fixed point of a substitution associated with a simple Parry number \\beta. It is shown that the word u_\\beta contains infinitely many palindromes if and only if t_1=t_2= ... =t_{m-1} \\geq t_m. Numbers \\beta satisfying this condition are the so-called confluent Pisot numbers. If t_m=1 then u_\\beta is an Arnoux-Rauzy word. We show that if \\beta is a confluent Pisot number then P(n+1)+ P(n) = C(n+1) - C(n)+ 2, where P(n) is the number of palindromes and C(n) is the number of factors of length n in u_\\beta. We then give a complete description of the set of palindromes, its structure and properties.", "revisions": [ { "version": "v1", "updated": "2006-03-26T13:31:56.000Z" } ], "analyses": { "subjects": [ "68R15", "11A63" ], "keywords": [ "simple parry number", "infinite words", "palindromic complexity", "confluent pisot number", "infinite aperiodic words" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......3608A" } } }