Published online by Cambridge University Press: 25 September 2007
We study some arithmetical and combinatorial properties ofβ-integers for β being the larger root of the equationx2 = mx - n,m,n ∈ ℵ, m ≥ n +2 ≥ 3. We determine withthe accuracy of ± 1 the maximal number of β-fractionalpositions, which may arise as a result of addition of twoβ-integers. For the infinite word uβ> coding distancesbetween the consecutive β-integers, we determine preciselyalso the balance. The word uβ> is the only fixed point of themorphism A → Am-1B and B → Am-n-1B. In the case n = 1,the corresponding infinite word uβ> is sturmian, and,therefore, 1-balanced. On the simplest non-sturmian example withn≥ 2, we illustrate how closely the balance and thearithmetical properties of β-integers are related.