2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/74537We study the problem of best approximations of a vector $α\in{\mathbb R}^n$ by rational vectors of a lattice $Λ\subset {\mathbb R}^n$ whose common denominator is bounded. To this end we introduce successive minima for a periodic lattice structure and extend some classical results from geometry of numbers to this structure. This leads to bounds for the best approximation problem which generalize and improve former results.8 pagesNumber Theory11J13; 11H06; 11H31; 52C07text