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JOURNAL OF
ALGEBRAIC
COMBINATORICS

  Editors-in-chief: C. A. Athanasiadis, T. Lam, A. Munemasa, H. Van Maldeghem
ISSN 0925-9899 (print) • ISSN 1572-9192 (electronic)
 

A generating function for all semi-magic squares and the volume of the Birkhoff polytope

J.A. De Loera , F. Liu and R. Yoshida
University of California Davis, Davis, CA 95616, USA

DOI: 10.1007/s10801-008-0155-y

Abstract

We present a multivariate generating function for all n\times  n nonnegative integral matrices with all row and column sums equal to a positive integer t, the so called semi-magic squares. As a consequence we obtain formulas for all coefficients of the Ehrhart polynomial of the polytope B n of n\times  n doubly-stochastic matrices, also known as the Birkhoff polytope. In particular we derive formulas for the volumes of B n and any of its faces.

Pages: 113–139

Keywords: keywords Birkhoff polytope; volume; lattice points; generating functions; Ehrhart polynomials

Full Text: PDF

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