Pal's permanent conjecture: proof for block uniform matrices
Abstract
Consider a symmetric function π(x,y) on [0,1]Γ[0,1] which is twice continuously differentiable up to the boundary, and which satisfies $ \mathcal{C}(x,y)=\mathcal{C}(1-x,1-y)$. Let A(n) = (a(n)i,j : i,j β [n]) be the matrix with entries a(n)i,j = exp(βπ(i/n,j/n)). Soumik Pal conjectured the asymptotics perm(A(n))/n!βΌ exp(n Ξ[π])/ β(π[π]) as n β β for known functionals that arise naturally in the context of entropy regularized optimal transport. The functional Ξ[π] is the known large deviation rate function, already proved rigorously by Sumit Mukherjee. It is β«01 β«01 (Ξ±(x)+Ξ²(y)) dx dy where Ξ±(x)+Ξ²(y) is chosen such that Ο(x,y) := exp(βπ(x,y)βΞ±(x)βΞ²(y)) has uniform marginals. The algebraic term π[c] is given by Peter McCullagh's formula for doubly stochastic matrices: detF(I+JβT*T), the Fredholm determinant, where I is the identity on L2([0,1]), Jf(x) β‘ β«01 f(z) dz (for all x) and Tf(x) = β«01 Ο(x,y) f(y) dy. We prove the conjecture for functions π that are constant on blocks, exploiting a well-known Ross Pinsky's combinatorial decomposition of permutations in blocks.
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BibTeX
@misc{ottolini2026pals,
title = {{Pal's permanent conjecture: proof for block uniform matrices}},
author = {Andrea Ottolini and Shannon Starr},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.25274},
eprint = {2605.25274},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.25274},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Pal's permanent conjecture: proof for block uniform matrices
AU - Andrea Ottolini
AU - Shannon Starr
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2605.25274
UR - https://arxiv.org/abs/2605.25274
AB - Consider a symmetric function π(x,y) on [0,1]Γ[0,1] which is twice continuously differentiable up to the boundary, and which satisfies $ \mathcal{C}(x,y)=\mathcal{C}(1-x,1-y)$. Let A^(n) = (a^(n)_i,j : i,j β [n]) be the matrix with entries a^(n)_i,j = exp(βπ(i/n,j/n)). Soumik Pal conjectured the asymptotics perm(A^(n))/n!βΌ exp(n Ξ[π])/ β(π[π]) as n β β for known functionals that arise naturally in the context of entropy regularized optimal transport. The functional Ξ[π] is the known large deviation rate function, already proved rigorously by Sumit Mukherjee. It is β«_0^1 β«_0^1 (Ξ±(x)+Ξ²(y)) dx dy where Ξ±(x)+Ξ²(y) is chosen such that Ο(x,y) := exp(βπ(x,y)βΞ±(x)βΞ²(y)) has uniform marginals. The algebraic term π[c] is given by Peter McCullagh's formula for doubly stochastic matrices: det_F(I+JβT^*T), the Fredholm determinant, where I is the identity on L^2([0,1]), Jf(x) β‘ β«_0^1 f(z) dz (for all x) and Tf(x) = β«_0^1 Ο(x,y) f(y) dy. We prove the conjecture for functions π that are constant on blocks, exploiting a well-known Ross Pinsky's combinatorial decomposition of permutations in blocks.
ER -