2022/11/08 by Reynold Fregoli, Dmitry Kleinbock, Fregoli, Reynold +1
Mathematics · #11H06 #11J13 #11J83 #37A44 #Advanced Banach Space Theory #Approximation Theory and Sequence Spaces #FOS: Mathematics #Fixed Point Theorems Analysis #Number Theory (math.NT)
paper · pdf · doi:10.48550/arxiv.2211.04523
openalex publication_date 2022/11/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Let ⟨ x⟩ denote the distance from x∈ℝ to the set of integers ℤ. The Littlewood Conjecture states that for all pairs (α,β)∈ℝ2 the product q⟨ qα⟩⟨ qβ⟩ attains values arbitrarily close to 0 as q∈ℕ tends to infinity. Badziahin showed that if a factor log q⋅ loglog q is added to the product, the same statement becomes false. In this paper, we generalise Badziahin's result to vectors \boldsymbolα∈ℝd, replacing the function log q⋅ loglog q by (log q)d-1⋅loglog q for any d≥ 2, and thereby obtaining a new proof in the case d=2. Our approach is based on a new version of the well-known Dani Correspondence between Diophantine approximation and dynamics on the space of lattices, especially adapted to the study of products of rational approximations. We believe that this correspondence is of independent interest.