2005/04/28 by Jonathan M. Groves, Groves, Jonathan M., Yonatan Harel +7
Mathematics · #05A15 #15A21 #15A24 #46B20 #FOS: Mathematics #Operator Algebras (math.OA) #math.OA #msc:05A15 #msc:15A21 #msc:15A24 #msc:46B20
paper · pdf · doi:10.48550/arxiv.math/0504572
11 pages, Electronic Journal of Linear Algebra
arxiv created 2005/04/28 · arxiv updated 2009/12/01
A real n-by-n idempotent matrix A with all entries having the same absolute value is called \it absolutely flat. We consider the possible ranks of such matrices and herein characterize the triples: size, constant, and rank for which such a matrix exists. Possible inequivalent examples of such matrices are also discussed.