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Cohen-Lenstra distribution for sparse matrices with determinantal biasing

Probability 2024-10-07 v2 Combinatorics

Abstract

Let us consider the following matrix BnB_n. The columns of BnB_n are indexed with [n]={1,2,,n}[n]=\{1,2,\dots,n\} and the rows are indexed with [n]3[n]^3. The row corresponding to (x1,x2,x3)[n]3(x_1,x_2,x_3)\in [n]^3 is given by i=13exi\sum_{i=1}^3 e_{x_i}, where e1,e2,,ene_1,e_2,\dots,e_n is the standard basis of R[n]\mathbb{R}^{[n]}. Let AnA_n be random n×nn\times n submatrix of BnB_n, where the probability that we choose a submatrix CC is proportional to det(C)2|\det(C)|^2. Let p5p\ge 5 be a prime. We prove that the asymptotic distribution of the pp-Sylow subgroup of the cokernel of AnA_n is given by the Cohen-Lenstra heuristics. Our result is motivated by the conjecture that the first homology group of a random two dimensional hypertree is also Cohen-Lenstra distributed.

Cite

@article{arxiv.2307.04741,
  title  = {Cohen-Lenstra distribution for sparse matrices with determinantal biasing},
  author = {András Mészáros},
  journal= {arXiv preprint arXiv:2307.04741},
  year   = {2024}
}
R2 v1 2026-06-28T11:26:18.096Z