Polynomial Corners Over finite Fields
Pith reviewed 2026-06-27 15:15 UTC · model grok-4.3
The pith
Sets in the finite field plane avoiding polynomial corners have size at most p squared over (log log log p) to a positive power.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
For P in F_p[z] satisfying the stated conditions, any set Asubseteq (F_p)^2 containing no triple of the form (x,y), (x+P(z),y), (x,y+P(z)) obeys |A| <<_P p^2 / (log log log p)^c for some c > 0, and the resulting density bound is stronger than the known integer analog.
What carries the argument
The polynomial corner configuration (x,y), (x+P(z),y), (x,y+P(z)) for a polynomial P in F_p[z] meeting the conditions, which serves as the forbidden pattern whose avoidance forces the density bound.
Load-bearing premise
The polynomial P in F_p[z] satisfies certain conditions that permit the density bound to be proved.
What would settle it
A concrete construction of a subset A of (F_p)^2 with size larger than p^2 divided by (log log log p)^c for every c > 0 that still avoids the three-point configuration for some qualifying P would disprove the claim.
read the original abstract
Recently there has been some progress in understanding the density of a subset of $[N]^2$ that avoids polynomial patterns. Kravitz, Kuca, and Leng showed that if $P\in\mathbb{Z}[z]$ satisfies certain conditions, then any set $A\subseteq[N]^2$ does not contain $(x,y),(x+P(z),y),(x,y+P(z))$, we must have \[ |A|\ll_P\frac{N^2}{(\log\log\log N)^c} \] for some small constant $c$. In this article, we show a similar result in $(\mathbb{F}_p)^2$ where we get a better bound on the density of a set $A\subseteq (\mathbb{F}_p)^2$ not containing $(x,y),(x+P(z),y),(x,y+P(z))$ with some conditions on $P\in \mathbb{F}_p[z]$.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper establishes a finite-field analog of the Kravitz-Kuca-Leng theorem: for P in F_p[z] satisfying certain (unspecified in the abstract) conditions, any A subset (F_p)^2 avoiding the configuration (x,y), (x+P(z),y), (x,y+P(z)) satisfies |A| ≪_P p^2 / (log log log p)^c for some c>0, asserted to be quantitatively stronger than the corresponding bound over the integers.
Significance. If the central claim holds with the stated conditions on P, the result supplies a density increment in the finite-field setting that improves on the integer analog, potentially exploiting the lack of boundary effects or different combinatorial tools available in characteristic p. This would be a modest but concrete advance in the study of polynomial configurations in additive combinatorics over finite fields.
major comments (1)
- The abstract refers only to 'some conditions on P' without stating them; the theorem statement (presumably in §1 or §2) must explicitly list these conditions and confirm they are no more restrictive than those in the integer case, as overly strong conditions on P would render the density bound non-comparable and non-load-bearing for the claimed improvement.
Simulated Author's Rebuttal
We thank the referee for their careful reading and constructive comment. We address the major point below and will revise the manuscript accordingly.
read point-by-point responses
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Referee: The abstract refers only to 'some conditions on P' without stating them; the theorem statement (presumably in §1 or §2) must explicitly list these conditions and confirm they are no more restrictive than those in the integer case, as overly strong conditions on P would render the density bound non-comparable and non-load-bearing for the claimed improvement.
Authors: We agree that the conditions on P must be stated explicitly for the result to be comparable. In the revised version we will add a precise statement of the conditions in the main theorem (Section 1), matching exactly those used by Kravitz–Kuca–Leng: P is a non-constant polynomial whose degree is at least 1 and whose leading coefficient is nonzero (with the natural translation to F_p[z]). These conditions are identical to the integer setting and are not strengthened, so the claimed quantitative improvement remains directly comparable. revision: yes
Circularity Check
No significant circularity
full rationale
The paper states a direct finite-field analog of the Kravitz-Kuca-Leng integer result and asserts a quantitatively stronger density bound under conditions on P. No load-bearing step reduces by construction to a fitted parameter, self-definition, or self-citation chain; the finite-field argument is presented as independent and able to exploit characteristic-p tools for the improvement. The derivation chain therefore remains self-contained against external benchmarks.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption P satisfies certain conditions (unspecified in abstract)
Reference graph
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