2017/04/26 by Alberto Borobia, Borobia, Alberto
Mathematics · #15A83 #Combinatorics (math.CO) #FOS: Mathematics #math.CO #msc:15A83
paper · pdf · doi:10.48550/arxiv.1704.08037
3 pages
arxiv created 2017/04/26 · arxiv updated 2017/04/27
Fillmore Theorem says that if A is a nonscalar matrix of order n over a field \mathbbF and γ1,…,γn∈ \mathbbF are such that γ1+⋯+γn=tr A, then there is a matrix B similar to A with diagonal (γ1,…,γn). Fillmore proof works by induction on the size of A and implicitly provides an algorithm to construct B. We develop an explicit and extremely simple algorithm that finish in two steps (two similarities), and with its help we extend Fillmore Theorem to integers (if A is integer then we can require to B to be integer).