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Planar Point Sets with Many Unit Distances

2026 technical research paper, 2026 · paper · Mathematics and statistics

Proves that the maximum number of unit-distance pairs among n planar points is at least n^(1+δ) for some fixed δ>0 and infinitely many n, disproving the Erdős unit distance conjecture. The construction uses towers of number fields.

Checked: PDF from cdn.openai.com, fetched 5 Oct 2026. Page numbers are those of that PDF.

2 findings

Wording Equation (4) on page 4 prints "rd(K_j) ≤ 2, rd(F) =: A_ℓ." with a comma and wide space between 2 and rd(F); as printed the bound rd(K_j) ≤ 2 is false, and the intended reading is evidently "rd(K_j) ≤ 2 rd(F) =: A_ℓ", as in P5 and Step 4 on pages 12 and 14.
  • p. 4 Final Response from Internal Model, equation (4)
    rd(K_j) ≤ 2, rd(F) =: A_ℓ.
  • p. 14 Proof of Proposition 3.8, Step 4
    rd(K_j) ≤ 2 rd(F)

Only the authors can say what is right here.

Judge's note: Viewed the page 4 and page 14 images. On page 4, equation (4) shows "rd(K_j) ≤ 2," then a quad space, then "rd(F) =: A_ℓ.", so this is in the PDF and not an extraction artefact. My reworking: K_j = F_j(i) is quadratic over F_j, so |D_{K_j}| = |D_{F_j}|^2 · N(relative discriminant) ≥ |D_{F_j}|^2. Taking 2f_j-th roots gives rd(K_j) ≥ rd(F_j) = rd(F). By equation (3), rd(F) = D^{2/3}, with D a product of primes ≡ 1 (mod 3), so D ≥ 7 and rd(F) ≥ 7^{2/3} > 2 (since 49 > 8). Hence rd(K_j) ≤ 2 cannot hold. Because the relative discriminant divides (4), N ≤ 4^{f_j}, which gives rd(K_j) ≤ 2 rd(F); this is exactly what page 14 Step 4 and property P5 (page 12) state. The step is faulty as printed but the stated result stands, so S3. The passage is inside the quoted "Final Response from Internal Model", so the authors must decide whether to amend the quoted text or annotate it.

Second check: another model agreed

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Wording "and the quotient Gal(M/F) has rank ℓ − 1": in the context of Gal(M/Q) ≅ (Z/3Z)^ℓ, Gal(M/F) is the subgroup fixing F (the kernel of χ), not a quotient; the quotient is Gal(F/Q) of rank 1.
  • p. 10 Proof of Proposition 3.2, first paragraph
    and the quotient Gal(M/F) has rank ℓ−1

Judge's note: Page 10 image, proof of Proposition 3.2: the sentence follows "giving the displayed Galois group for M/Q. The product character χ cuts out a cyclic cubic subfield F ⊂ M". With Q ⊂ F ⊂ M, Gal(M/F) is a subgroup of Gal(M/Q); the stated rank ℓ−1 is right for that subgroup. Only the word "quotient" is wrong, and the mathematics is unaffected. Page 13 correctly calls (Z/3Z)^{ℓ−1} a quotient of G = Gal(F^{ur,3}/F), which is a different ambient group.

Second check: another model agreed

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9 minor (typos and the like; most checked by the judge only)
Wording Display numbers are used twice: the paper's own "ν(n) ≤ n^{1+C/ log log n}. (1)" (p1) and "s = 1, . . . , m. (2)" (p6) share numbers with the reproduced model output's "d(G) ≥ ℓ−1. (1)" and "r(G) ≤ d(G) + C0 (2)" (p4), so references such as "translation in U by (3)" are not unique by number alone.
  • p. 1 Section 1, display (1)
    ν(n) ≤n1+C/ log log n. (1)
  • p. 4 Final Response from Internal Model, display (1)
    d(G) ≥ℓ−1. (1)
  • p. 6 Section 2, display (2)
    s = 1, . . . , m. (2)
  • p. 4 Final Response from Internal Model, display (2)
    r(G) ≤d(G) + C0 (2)

Judge's note: Checked pages 1, 4, 5 and 6 on the images: the reproduced block numbers its displays (1)-(11), while the paper proper has (1) on p1 and (2) on p6. The text layer shows the paper's own (3)-(4) and (5)-(7) further on, so numbers 1-7 each label two displays. The block is set off in italics and described as verbatim, so context resolves each reference; this is a minor ambiguity where separate numbering may be intended. The second reviewer note ("repeated log") is not a defect: "log log n" is the iterated logarithm.

Second check: another model agreed, code check

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Wording In the reproduced model proof, C0 is first "an absolute constant C0" in r(G) ≤ d(G) + C0 (2). Later it becomes "Given arbitrary C0 > 0 and N, choose j so large that ... C0/ log log nj < δ", and the closing sentence then refers to "universal constants C, N".
  • p. 4 Final Response from Internal Model, display (2) and following line
    with an absolute constant C0
  • p. 6 Final Response from Internal Model, after display (11)
    Given arbitrary C0 > 0 and N
  • p. 6 Final Response from Internal Model, after (11)
    Given arbitrary C0 > 0 and N, choose j so large that nj ≥ N and C0/ log log nj < δ.
  • p. 4 Final Response, eq. (2)
    r(G) ≤d(G) + C0

Judge's note: I checked p.4 (display (2) and the line after it) and p.6 (the text after (11)). The same symbol C0 is declared as the absolute Shafarevich constant, which feeds the choice of ℓ, t, γ, B and δ, and is later reintroduced as an arbitrary constant standing for the C of the conjecture. The meaning can be recovered from context, and the final sentence itself uses C. The passage is announced as verbatim model output (text line 134). This is a notation clash within one argument; the mathematics is not affected.

Second check: another model agreed

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Typo Stray parentheses around the hypothesis in the reproduced model output: "First, if (g1, . . . , gk ∈Φ(G)), then the quotient" should read "if g1, . . . , gk ∈ Φ(G), then".
  • p. 3 Final Response from Internal Model, first paragraph
    First, if (g1, . . . , gk ∈Φ(G)), then the quotient
  • p. 3 model's final response, first standard fact
    if (g1, . . . , gk ∈ Φ(G))

Judge's note: Page 3 image prints the parentheses around the whole membership statement. They look like inline-math delimiters rendered literally. The meaning is clear, so this is cosmetic. The block is said to be reproduced verbatim, so the defect may be in the original output.

Second check: none (judge only)

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Typo Display (4) in the reproduced model output prints "rd(Kj) ≤ 2, rd(F) =: Aℓ." A stray comma splits what is evidently the bound rd(Kj) ≤ 2 rd(F) =: Aℓ.
  • p. 4 Final Response from Internal Model, display (4)
    rd(Kj) ≤2, rd(F) =: Aℓ.
  • p. 12 Proposition 3.8 (P5)
    rd(Kj) ≤2 rd(F)
  • p. 14 Step 4
    gives rd(Kj) ≤2 rd(F)
  • p. 4 Final Response from Internal Model, display (4)
    rd(Kj) ≤ 2,

Judge's note: I checked the crop and page 4. The comma and the wide gap appear in display (4) on the page image, so this is not an extraction artefact. The sentence before the display says the relative discriminant of adjoining i divides 4. That gives |D_K| ≤ |D_F|^2·4^f, and taking 2f-th roots gives rd(K) ≤ 2 rd(F). (P5) on p.12 states exactly this, and Step 4 on p.14 derives the same thing ('rd(Kj) ≤ 2 rd(F)'), so the stray comma looks like a thin space rendered as punctuation. Read literally, the display states the bound rd(Kj) ≤ 2 and defines Aℓ as rd(F). Line 134 of the text says the block is reproduced verbatim from the model output, so the slip may come from that output. It is still the printed equation. The detailed exposition has the correct form and the result is unaffected, so I rate it as a punctuation typo.

Second check: none (judge only)

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Typo Set braces are missing in the reproduced model output: "ai ∈ 0, 1, 2" (p4), "For ϵ = (ϵs) ∈ 0, 1m" and "are in −2, 0, 2" (p5); these should be {0, 1, 2}, {0, 1}^m and {−2, 0, 2}.
  • p. 4 Final Response from Internal Model, paragraph before the display |D_M| = …
    ai ∈0, 1, 2
  • p. 5 Final Response from Internal Model, definition of the ideals
    For ϵ = (ϵs) ∈0, 1m
  • p. 5 Final Response from Internal Model, valuations of u
    are in −2, 0, 2
  • p. 5 paragraph before definition of Aϵ
    For ϵ = (ϵs) ∈ 0, 1m put

Judge's note: Pages 4 and 5 images confirm the braces are absent in the PDF in all three places, not lost in extraction. The paper's own proof of Proposition 2.2 prints "{0, 1}m" with braces (p7, from the text layer). Unescaped LaTeX braces were probably dropped when the output was typeset. The meaning is recoverable.

Second check: none (judge only)

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Typo Set braces are missing in the reproduced model output: "a_i ∈ 0, 1, 2" (p. 4) and "are in −2, 0, 2, so" (p. 5) should read {0, 1, 2} and {−2, 0, 2}.
  • p. 5 Final Response from Internal Model, paragraph after the definition of u_ϵ
    are in −2, 0, 2, so
  • p. 4 model's final response, characters of M
    ai ∈ 0, 1, 2
  • p. 5 valuations of uϵ
    are in −2, 0, 2

Judge's note: Checked both page images. Page 4 prints "a_i ∈ 0, 1, 2" and page 5 prints "are in −2, 0, 2" with no braces. The same page 5 also prints "ϵ = (ϵ_s) ∈ 0, 1^m" for {0,1}^m, so the braces were lost systematically in this quoted block. Cosmetic; the meaning is recoverable.

Second check: none (judge only)

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Typo Display (9) in the reproduced model output prints "ν(Pj) ≥ 1/2 e^{γfj/2}, nj." A stray comma separates the factor nj from the product, which should read ν(Pj) ≥ ½ e^{γfj/2} nj.
  • p. 5 Final Response from Internal Model, display (9)
    2eγfj/2, nj.
  • p. 9 Proof of Theorem 2.3
    ν(Pj) ≥1 2njeγfj/2
  • p. 9 Proof of Theorem 2.3
    2njeγfj/2,
  • p. 5 Final Response from Internal Model, display (9)
    ν(Pj) ≥ 1/2 e^{γfj/2}, nj.

Judge's note: I checked the crop of p.5 and the page image: the comma between e^{γfj/2} and nj is really printed there. The bound follows from (8): D_y ≥ e^{γfj/2}|X|, with each segment counted at most twice. Step (11) needs the factor nj. The proof of Theorem 2.3 on p.9 prints the correct form, ν(Pj) ≥ ½ nj e^{γfj/2}. This is the same comma-for-thin-space slip as in (4), inside a block announced as verbatim model output. It is a punctuation typo and the result is unaffected.

Second check: none (judge only)

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Typo Subscripts are set on the baseline in the reproduced output: "so the uϵ's are distinct" (for u_ϵ) and "Q²u_ϵ ∈ 𝒪K_j" (for 𝒪_{K_j}).
  • p. 5 Final Response from Internal Model, sentence before display (7)
    so the uϵ’s are distinct
  • p. 5 Final Response from Internal Model, same paragraph
    Q2uϵ ∈OKj

Judge's note: Page 5 image: "uϵ's" is in running italic with ϵ on the baseline, while u_ϵ carries a subscript elsewhere in the block. "𝒪K_j" has K at full size after 𝒪, whereas three lines below "Λ_j = Q^{-2}𝒪_{K_j}" is set correctly. Typesetting slip only.

Second check: none (judge only)

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Typo Duplicated statement: "By Golod-Shafarevich, again as stated in Proposition 3.4, Ḡ is infinite. Thus Ḡ is infinite, and the selected Frobenius classes are trivial in it."
  • p. 13 Step 2, last paragraph
    G is infinite. Thus G is infinite, and the selected Frobenius classes are trivial
  • p. 13 Proof of Proposition 3.8, end of Step 2
    is infinite, and the selected Frobenius classes are trivial
  • p. 13 Step 2, last paragraph
    Ḡ is infinite. Thus Ḡ is infinite, and the selected Frobenius classes are trivial
  • p. 13 Step 2, last paragraph
    Thus G is infinite

Judge's note: Page 13 image, end of Step 2: both occurrences carry the overline (Ḡ), so the second sentence restates the first as if it were a new deduction. An editing leftover with no effect on the argument.

Second check: none (judge only)

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