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arXiv · 0709.3810

Asymptotic estimates for the number of contingency tables, integer flows, and volumes of transportation polytopes

Alexander Barvinok
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Abstract

We prove an asymptotic estimate for the number of mxn non-negative integer matrices (contingency tables) with prescribed row and column sums and, more generally, for the number of integer feasible flows in a network. Similarly, we estimate the volume of the polytope of mxn non-negative real matrices with prescribed row and column sums. Our estimates are solutions of convex optimization problems and hence can be computed efficiently. As a corollary, we show that if row sums R=(r_1, ..., r_m) and column sums C=(c_1, ..., c_n) with r_1 + ... + r_m =c_1 + ... +c_n =N are sufficiently far from constant vectors, then, asymptotically, in the uniform probability space of the mxn non-negative integer matrices with the total sum N of entries, the event consisting of the matrices with row sums R and the event consisting of the matrices with column sums C are positively correlated.

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Alexander Barvinok. 2008-08-21. Asymptotic estimates for the number of contingency tables, integer flows, and volumes of transportation polytopes. https://arxiv.org/abs/0709.3810

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