A Dynamical Proof of Pisot's Theorem
Jarosław Kwapisz · Canadian Mathematical Bulletin · 2006
Abstract We give a geometric proof of classical results that characterize Pisot numbers as algebraic λ > 1 for which there is x ≠ 0 with λnx → 0 (mod 1) and identify such x as members of ℤ[λ–1]· ℤ[λ]* where ℤ[λ]* is the dual module of ℤ[λ].