%0 Journal Article
%T Proof of the monotone column permanent conjecture
%A Petter Br£¿nd¨¦n
%A James Haglund
%A Mirk¨® Visontai
%A David G. Wagner
%J Mathematics
%D 2010
%I arXiv
%X Let A be an n-by-n matrix of real numbers which are weakly decreasing down each column, Z_n = diag(z_1,..., z_n) a diagonal matrix of indeterminates, and J_n the n-by-n matrix of all ones. We prove that per(J_nZ_n+A) is stable in the z_i, resolving a recent conjecture of Haglund and Visontai. This immediately implies that per(zJ_n+A) is a polynomial in z with only real roots, an open conjecture of Haglund, Ono, and Wagner from 1999. Other applications include a multivariate stable Eulerian polynomial, a new proof of Grace's apolarity theorem and new permanental inequalities.
%U http://arxiv.org/abs/1010.2565v2