Proof of the monotone column permanent conjecture
Combinatorics
2013-04-23 v2
Abstract
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.
Cite
@article{arxiv.1010.2565,
title = {Proof of the monotone column permanent conjecture},
author = {Petter Brändén and James Haglund and Mirkó Visontai and David G. Wagner},
journal= {arXiv preprint arXiv:1010.2565},
year = {2013}
}