The Characterization of Rational Numbers Belonging to a Minimal Path in the Stern-Brocot Tree According to a Second Order Balancedness

Autor: Andrea Frosini, Lama Tarsissi
Rok vydání: 2020
Předmět:
Zdroj: Developments in Language Theory ISBN: 9783030485153
DLT
DOI: 10.1007/978-3-030-48516-0_24
Popis: In 1842, Dirichlet observed that any real number \(\alpha \) can be obtained as the limit of a sequence \((\frac{p_n}{q_n})\) of irreducible rational numbers. Few years later, M. Stern (1858) and A. Brocot (1861) defined a tree-like arrangement of all the (irreducible) rational numbers whose infinite paths are the Dirichlet sequences of the real numbers and are characterized by their continued fraction representations. The Stern-Brocot tree is equivalent to the Christoffel tree obtained by ordering the Christoffel words according to their standard factorization. We remark that the Fibonacci word’s prefixes belong to a minimal path in the Christoffel tree with respect to the second order balancedness parameter defined on Christoffel words. This alows us to switch back to the Stern-Brocot tree, in order to give a characterization of the continued fraction representation for all the rational numbers belonging to minimal paths with respect to the growth of the second order balancedness.
Databáze: OpenAIRE