The length spectrum of q-discrete Painlevé I over a finite field: an exact form of the bin conjecture at prime q, and verification past the published range
Abstract
Joshi and Roffelsen have shown that the q-discrete first Painlevé equation, resolved on Sakai's initial value space, defines a bijection of a set of (q+1)² points over a finite field 𝔽_q, and they conjecture on the strength of a Magma computation over every prime power 2 ≤ q ≤ 499 that every reduced orbit length obeys the Hasse bound q+2sqrt q+1 and in fact lies in one of M_q explicit disjoint intervals, the bins. We report four things about the set of reduced orbit lengths that is actually realised. First, for every prime q with 3 ≤ q ≤ 131 the conjectured containment is an equality: every integer in every bin other than 2 and 3 occurs as a reduced orbit length, and nothing else does. This fails at the proper prime powers q=4,9,25,128, so the phenomenon is one of prime q. Second, the largest reduced orbit length is exactly q+1+max{d ∈ ℕ:d²<4q}, the largest integer strictly below the Hasse bound, at every prime power q ≤ 131 except q=128, where it falls one short. Third and fourth, both conjectures hold for all 3 534 638 orbits over 𝔽₅₀₃, the first prime power past the published range, and for all 5 756 256 orbits over 𝔽₁₀₀₉ whose parameter s is one of the twelve smallest elements of 𝔽₁₀₀₉^ ×, where M_q=8 against M₄₉₉=6. All statements are formally verified in Lean 4; every search is exhaustive over the range stated and is described.
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Archived files
- Version 1 · current (opens in a new tab)
Source snapshot 2026-08-30 15:34 UTC
File fingerprint
f62646d401a1eca062cd2d189b778977f8731279ae8eb9a054e7c8201126fd99
Claim ledger
Stated results
QP1known data2026-08-30
Compute-first gate: every number the source prints reproduced – the q=2, q=3 and q=4 orbits, the full q=5 frequency lists L₁, L₂, L₄, and the q=499 bin frequencies 113831/54446/13551/19140/6935/42097 summing to 250000
QP2routine2026-08-30
M_q and the bins Bₘ of Conjecture 1.2.B in exact integer arithmetic (no square roots), reproducing the source's printed q=499 bins [456,544], [228,272], [152,181], [114,136], [92,108], [1,90]
QP3candidate2026-08-30
The maximum reduced orbit length is exactly q + 1 + maxd: d² < 4q, the largest integer strictly below the Hasse bound, at every prime power q <= 131 except q = 128 – and at q = 503 and q = 1009
QP4routine2026-08-30
Negative controls: the 2 sqrt q term cannot be dropped (reduced length 7 > q+1 at q = 3); the sharpness statement is not a theorem for all q (at q = 128 the maximum is 150, not 151); the bins are strictly stronger than the Hasse bound (78 passes the bound at q = 131 but lies in no bin); and the sweep is not vacuous
QP5candidate2026-08-30
q-Painleve I over F₅03: Conjectures 1.2.A and 1.2.B hold for all 3 534 638 orbits, over every s in F₅03^* and every coset, with maximum reduced orbit length 548 and minimum 1
QP6routine2026-08-30
The kernel band: Conjectures 1.2.A and 1.2.B for every orbit over F₂, F₃, F₅, F₇ with no native_decide axiom, plus a cross-check that the array engine and the array-free kernel engine return the same maxima
QP7routine2026-08-30
What the integer checks mean, and two facts at every q: hasseOK is equivalent to #(gamma)/r <= q + 2 sqrt q + 1, inBin is exactly the integer test (mL-(q+1))² <= 4q and that test is membership in Bₘ, consecutive bins below M_q are disjoint, and ord(s) divides the period of any state with nonzero time over an arbitrary field
QP8known data2026-08-30
The source's Magma verification re-run from scratch: Conjectures 1.2.A and 1.2.B for every orbit at all 45 prime powers q <= 131 (44 in one sweep, q = 128 separately), 3 327 974 orbits, on an independent implementation
QP9candidate2026-08-30
q-Painleve I over F₁009, more than twice the source's range: Conjectures 1.2.A and 1.2.B hold for all 5 756 256 orbits with s among the twelve smallest elements of F₁009^*, M_q = 8, maximum reduced orbit length 1073 = hasseStrictMax 1009
QP10candidate2026-08-30
Conjecture 1.2.B is an equality for prime q: the set of realised reduced orbit lengths is exactly the union of the M_q bins with 2 and 3 removed, at every prime 3 <= q <= 131; and this fails at proper prime powers (4, 9, 25, 128)
Provenance
- Generated by
- Machina Mathematica
- Released by
- Korea Superintelligence Labs
- Source context
- Joshi and Roffelsen (arXiv:2508.18578v2, *Arithmetic dynamics of a discrete Painlevé equation*, nlin.SI / math.DS, MSC 39A13 33E17 37P05 11G20) study the q-discrete first Painlevé equation
- Snapshot
- 2026-09-07 03:53 UTC
- Ledger commit
801848d7