Cheong–Huang–Kaplan conjecture on cokernels of polynomial functions of random matrices

About 4 years old · traced to

Fix finitely many monic polynomials P1(t),…,Pl(t)∈Zp[t]P_{1}(t),\dots,P_{l}(t)\in\mathbb{Z}_{p}[t] whose images in Fp[t]\mathbb{F}_{p}[t] modulo pp are distinct and irreducible. For 1≤j≤l1\leq j\leq l, let GjG_{j} be a finite module over Zp[t]/(Pj(t))\mathbb{Z}_{p}[t]/(P_{j}(t)). For Xˉ∈Mat⁡n(Fp)\bar{X}\in\operatorname{Mat}_{n}(\mathbb{F}_{p}) satisfying cok⁡(Pj(Xˉ))≃Gj/pGj\operatorname{cok}(P_{j}(\bar{X}))\simeq G_{j}/pG_{j} for 1≤j≤l1\leq j\leq l, consider lifts X∈Mat⁡n(Zp)X\in\operatorname{Mat}_{n}(\mathbb{Z}_{p}). Cheong–Huang–Kaplan's conjecture. The probability that cok⁡(Pj(X))≃Gj\operatorname{cok}(P_{j}(X))\simeq G_{j} for 1≤j≤l1\leq j\leq l and X≡Xˉ(modp)X\equiv\bar{X}\pmod p is

Prob⁡X∈Mat⁡n(Zp)(cok⁡(Pj(X))≃Gjfor 1≤j≤land X≡Xˉ(modp))=p−n2∏j=1lpdeg⁡(Pj)(dim⁡Fp[t]/(Pj(t))(Gj/pGj))2∣Aut⁡Zp[t]/(Pj(t))(Gj)∣∏i=1dim⁡Fp[t]/(Pj(t))(Gj/pGj)(1−p−ideg⁡(Pj))2.\underset{X\in\operatorname{Mat}_{n}(\mathbb{Z}_{p})}{\operatorname{Prob}}\left(\begin{array}{c} \operatorname{cok}(P_{j}(X))\simeq G_{j} \\ \text{for }1\leq j\leq l \\ \text{and } X\equiv\bar{X}\pmod p \end{array}\right)=p^{-n^{2}}\prod_{j=1}^{l}\frac{p^{\deg(P_{j})(\dim_{\mathbb{F}_{p}[t]/(P_{j}(t))}(G_{j}/pG_{j}))^{2}}}{|\operatorname{Aut}_{\mathbb{Z}_{p}[t]/(P_{j}(t))}(G_{j})|}\prod_{i=1}^{\dim_{\mathbb{F}_{p}[t]/(P_{j}(t))}(G_{j}/pG_{j})}(1-p^{-i\deg(P_{j})})^{2}.

The conjecture extends the paper's main theorem and is described as work in progress by Cheong, Huang, and Kaplan. It is intended as a non-asymptotic formula for joint cokernel distributions of polynomial expressions in random matrices, generalizing earlier results on random integral matrices.

References

Primary source

Gilyoung Cheong, Yunqi Liang and Michael Strand, “Polynomial equations for matrices over integers modulo a prime power and the cokernel of a random matrix”, arXiv:2209.03626 (2023).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.