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Follow-up (2026-09-27): more stale "open" labels, found by syncing with sources that maintain status data. Again, this is only meant to save others duplicated effort.

1. Erdős problems. All 632 EP-* entries are labelled open in v1.6.0. As of today, erdosproblems.com lists 90 of them as resolved (we fetched each page; many resolutions are recent, several by AI systems, and most are Lean-verified). Grouped by the site's status:

• Proved, Lean-verified (28): EP-38, EP-123, EP-126, EP-152, EP-258, EP-281, EP-283, EP-330, EP-351, EP-358, EP-369, EP-457, EP-469, EP-557, EP-571, EP-610, EP-750, EP-793, EP-825, EP-865, EP-987, EP-997, EP-1014, EP-1022, EP-1051, EP-1071, EP-1096, EP-1129
• Proved (9): EP-380, EP-591, EP-652, EP-851, EP-863, EP-986, EP-1021, EP-1105, EP-1130
• Disproved, Lean-verified (14): EP-1, EP-43, EP-74, EP-90, EP-125, EP-146, EP-180, EP-193, EP-533, EP-846, EP-847, EP-884, EP-990, EP-1092
• Disproved (8): EP-92, EP-543, EP-574, EP-575, EP-705, EP-869, EP-960, EP-992
• Solved otherwise (e.g. determined/answered), Lean-verified (12): EP-42, EP-119, EP-183, EP-190, EP-202, EP-318, EP-619, EP-650, EP-694, EP-696, EP-741, EP-888
• Solved otherwise (e.g. determined/answered) (19): EP-320, EP-321, EP-346, EP-387, EP-421, EP-477, EP-603, EP-625, EP-633, EP-690, EP-730, EP-783, EP-858, EP-896, EP-920, EP-948, EP-1005, EP-1089, EP-1091

The site's machine-readable status file (teorth/erdosproblems, data/problems.yaml) may be the easiest way to keep these entries in sync.

2. Ben Green's 100 open problems. The current version of the list (updated December 2025) marks these as solved. Note that the dataset's GREEN-xxx numbers differ from the numbering in Green's list.

3. OWR-1452-012 (Zhao's Vanishing Conjecture for homogeneous quartics). Zhao proved that this conjecture, over all n, is equivalent to the Jacobian conjecture over all n (Trans. AMS 359 (2007), arXiv:math/0409534). The July 2026 Jacobian counterexample (see SMA-016 above) therefore refutes it for some n; we have not identified the smallest such n.

— Alper Ferudun

Follow-up 2 (2026-09-27): Kourovka Notebook, issue 21 (KOU-21.*). The arXiv version of the notebook updated today (arXiv:1401.0300v46) marks the following issue-21 problems as solved (asterisk), while v1.6.0 still labels them open:

(The other nine starred issue-21 problems, 21.8, 21.12, 21.14, 21.15, 21.18, 21.24, 21.43, 21.58, 21.150, are already marked solved in the dataset.)

— Alper Ferudun

Follow-up 3 (2026-09-27): KOU-21.68 — new counterexample (our own result, unrefereed). Kourovka Notebook Problem 21.68 (M. Kida) conjectures that every finite semi-abelian group is monomial. This is false. There is a semi-abelian group of order 768 = 2^8·3 with a non-monomial irreducible character of degree 8:

• Ĝ = B ⋊ W, where W = E ⋊ A₄ is the index-two subgroup of C₂ ≀ A₄, T ≅ SL(2,3) ≤ W is the binary tetrahedral group acting on the eight quaternion units, and B is the augmentation (even-weight) submodule of the permutation module F₂[W/T].
• General reduction (Clifford theory): if a linear character of the abelian normal subgroup N has stabiliser T in W and T has a non-monomial irreducible character, then N ⋊ W is not an M-group.
• Checked by exact computation, including every subgroup of index 8 and the full character table of Ĝ (exactly the three degree-8 irreducible characters are non-monomial). Scripts are in the source archive.

Preprint: https://doi.org/10.5281/zenodo.23000305 · paper page: https://eulersolve.org/papers/kou-21-68/

Suggested label: solved (answered negatively). It has not been peer-reviewed yet, so independent checks are welcome. Minimality of the order is not claimed; Kida's Magma search covered all orders up to 240.

— Alper Ferudun

Follow-up 4 (2026-09-27): internal status inconsistency. For 188 problem numbers, the literature-triage block inside the record itself ("Literature review (checked 2026-08-17)", Status: solved, Classification: SOLVED-IN-LITERATURE) disagrees with the status field, which still says open (same in v1.6.0 and v1.7.0). 94 of them are already covered in the comments above; the remaining 94 are listed below by source so they can be reconciled in one pass. We have not re-verified each triage conclusion ourselves, and some of them refute a literal wording rather than the intended question, so they are pointers, not claims.

• HIL (1): HIL-009
• SMA (1): SMA-004
• NT (5): NT-008, NT-023, NT-035, NT-037, NT-086
• GREEN (3): GREEN-061, GREEN-064, GREEN-100
• GEO (3): GEO-004, GEO-006, GEO-028
• GEOM (1): GEOM-026
• GT (1): GT-008
• GRAPH (4): GRAPH-006, GRAPH-008, GRAPH-046, GRAPH-049
• TOP (1): TOP-003
• ALG (2): ALG-033, ALG-036
• COMB (2): COMB-012, COMB-004
• HL (1): HL-F
• GUY (3): GUY-A8a, GUY-A11, GUY-A15
• KP (6): KP-1.51, KP-3.14, KP-4.37, KP-4.125, KP-5.9, KP-5.15
• OPG (51): OPG-23298, OPG-50149, OPG-37185, OPG-426, OPG-1797, OPG-37167, OPG-37181, OPG-37230, OPG-692, OPG-37086, OPG-610, OPG-37341, OPG-34908, OPG-37081, OPG-37089, OPG-37218, OPG-37316, OPG-37364, OPG-57613, OPG-59952, OPG-59997, OPG-824, OPG-46606, OPG-47285, OPG-59911, OPG-2242, OPG-59994, OPG-616, OPG-36939, OPG-52200, OPG-47031, OPG-47643, OPG-37305, OPG-47646, OPG-677, OPG-690, OPG-691, OPG-735, OPG-177, OPG-157, OPG-732, OPG-760, OPG-2379, OPG-37444, OPG-37863, OPG-37402, OPG-655, OPG-1783, OPG-37245, OPG-37295, OPG-57401
• EP (9): EP-129, EP-520, EP-524, EP-545, EP-550, EP-612, EP-638, EP-654, EP-996 — note that erdosproblems.com still lists all nine as open (EP-550 as "open (Lean)"), so these triage conclusions deserve a second look before relabelling.

A JSON list (problem number, status field, triage status) is available on request.

— Alper Ferudun

Hello, thank you for these detailed additions! They are now integrated.

Follow-up 5 (2026-09-28): two new results, one problem already solved in the literature, and corrections to Oberwolfach and Kourovka records (stale statuses, transcription errors, merged records, one misattached note). Each item was checked against the current version (commit 2ea030b). Where a page is given, it was also checked in the report itself; literature was checked against arXiv and Crossref. Suggested changes are in bold.

New results (unrefereed preprints with full proofs, verification scripts and independent referee checks)

• OWR-12861-021 → solved (no). Heinig's Question 2 (OWR 01/2014, p. 82) has a negative answer for every odd n ≥ 7: K_{(n+1)/2,(n−1)/2} with a perfect matching (or a matching plus one P₃) inside the larger side has minimum degree ⌈n/2⌉ but no spanning copy of the near-square, under both readings of "periphery"; at n = 9, K_{4,4,1} is a counterexample under every reading. For n = 7 the host is Heinig's own graph X (arXiv:1112.5101, Def. 28). The cycle-space Question 1 is not affected (Hou–Yin). Paper: doi:10.5281/zenodo.23004012 (page).
• KOU-21.76 → solved. The existence question was first answered by Ya. N. Nuzhin, Sib. Math. J. 67 (2026) 840–845, Corollary 1 (examples in every characteristic, over F(y,z)); the notebook (v46) does not record this yet. Our note gives explicit examples with short proofs, including one-variable examples over F₃(t) (which also satisfy the hypotheses of 19.48), and shows that in characteristic 3 such nets exist over K iff K is not algebraic over F₃. Paper: doi:10.5281/zenodo.23004034 (page).

Stale statuses

• OWR-12330-013 → solved (yes). King answers his own Question 1 on the next page: "The answer to this is yes" (OWR 02/2013, p. 105). K_k with k pendant vertices at every vertex has χ_f = k > 3k/4 + 1 for k ≥ 5.
• OWR-1319-022 → solved (no). Two word metrics on H₃(ℤ)×ℤ have ratio → 1 but unbounded difference: Breuillard, Groups Geom. Dyn. (2014) (arXiv:0704.0095), and Breuillard–Le Donne, PNAS 110 (2013), §5, who cite this report.
• OWR-5158-016 → solved (yes). By Deroin–Hurtado (arXiv:2008.10687, Thm 1.3), irreducible lattices in finite-centre semisimple groups of real rank ≥ 2 are not left-orderable, so any cocompact arithmetic lattice in SL(3,ℝ) works. See also Witte Morris's exposition (2026).
• OWR-14213-006 → solved. The statement is the unit-interval (Hessenberg) form of the Stanley–Stembridge conjecture, proved by Hikita, J. Amer. Math. Soc. (2026) (arXiv:2410.12758).
• OWR-1386-016 → solved, if "threshold" has its usual coarse meaning (the constant b is then immaterial). This is the two-graph Kohayakawa–Kreuter conjecture: the 1-statement is due to Mousset–Nenadov–Samotij (CPC 2020), and Christoph–Martinsson–Steiner–Wigderson (Proc. LMS 130, 2025) completed the proof. A sharp threshold at b·n^(−1/m₂) would be a different question; we could not re-read the wording in OWR 48/2006.
• OWR-14299911-005 → solved (disproved). The source itself reports Chalopin–Chepoi's counterexample to the "MSO decidable ⇔ grid-free" conjecture (ACM TOCL 20 (2019)). Please also drop the second sentence: the special-cube-complex result concerns Thiagarajan's other conjecture, and the counterexample itself comes from a virtually special complex.
• OWR-17294-009 → at least partially solved. Part (1), Byott's question, is answered no by Di Matteo–Ferrara–Trombetti, arXiv:2607.22795 (July 2026 preprint). The record bundles Vendramin's Problems 1, 3 and 5 (OWR 51/2019, p. 3222); splitting it would help.
• KOU-21.115 → solved (yes). Sambale, arXiv:2609.09052 (September 2026 preprint), proves |G∖U| ≥ |G|/2ⁿ whenever n left cosets have union U ≠ G, and right cosets are left cosets of conjugates. The notebook (v46) has not starred it yet.
• OWR-4213-002 → solved. The statement is the Feit–Thompson theorem (Pacific J. Math. 13 (1963)). Also, "nontrivial" simple groups should read "non-abelian".
• OWR-1265-024 → not an open problem. The source poses it as a puzzle and gives the answer C(a+b,a) − C(a+b,a−1), which counts standard (b,a)-tableaux (G. James, OWR 15/2006, pp. 965–966).
• Pointer only, OWR-11568-005. Lutowski's Theorem 2 (Publ. Math. Debrecen 99 (2021)) says that the holonomy of a non-torus Kähler flat manifold has at least two distinct irreducible constituents. Since h^{1,1}(A/G) = dim End_G(T₀A), this seems to force b₂ ≥ 2 for free torus quotients of dimension ≥ 2. Worth a check.

Transcription errors

• OWR-12330-010, -011, -012: the ceilings in the source are missing (OWR 02/2013, p. 103, Conj. 3; p. 104, Conj. 4–6). As written, C₅ violates all of them: the right-hand sides are 5/2 or 3 − ε, while χ(C₅) = 3.
• OWR-1189-007: Kohl's Conjecture 2 reads ⌊3d(1−1/n)⌋ + 1, not ⌈·⌉ (OWR 7/2006, p. 416). As written it is false for d = 1 and n ≥ 4, because χ^{1,1}_ℓ(P_n) = ch(P_n²) = 3.
• OWR-5154-009: the source puts the profinite closure on the product [g₁]^F⋯[g_k]^F, not on N(g₁,…,g_k) (OWR 26/2011, p. 1452, Conj. 2). As written, the answer is trivially no.
• OWR-12007-008: with "r, s ∈ ℝ" (the same wording as OWR 35/2012, p. 2173) the question is false for w = a, since R(a,r,s) = r. The source's own results are for rational r, s, so this should read r, s ∈ ℚ.

Merged records

• OWR-4791-001 merges two conjectures that the organisers' introduction (OWR 1/2011, p. 6) reports as proved: Simonovits–Sós (Ellis–Filmus–Friedgut) and Sumner (for large n, Kühn–Mycroft–Osthus). Splitting it would help.
• OWR-9790352-039, OWR-10252930-031, OWR-9790352-036: the statement is already clean, but original_statement still contains a neighbouring item, respectively:
  • the Plummer–Zha conjecture, proved during the workshop (OWR 1/2022, p. 71; Chudnovsky–Seymour, JGT 103 (2023));
  • a weighted Turán conjecture, proved by Bradač (arXiv:2205.08923);
  • Narayanan's permanent inequality (OWR 1/2022, pp. 69–70), which is open and has no record of its own.

Misattached note

• OWR-12861-020: the literature note (Hou–Yin, arXiv:2503.15950) is about Heinig's Question 1 (OWR 01/2014, p. 81), which has no record of its own. It does not concern the Diestel or Friedgut questions in this record, and the record's "partially solved" label rests only on that note.

Correction to Follow-up 2. arXiv:1401.0300v46 (Kourovka Notebook No. 21) was posted on 1 September 2026, not on 27 September as I wrote there; the list of starred problems is unaffected.

— Alper Ferudun

Follow-up 6 (2026-09-28): three new results, and corrections to Oberwolfach combinatorics records (stale statuses, questions answered in their own source, transcription errors, duplicates, merged records, garbled extracts and misattached notes). Each item was checked against the current version (commit 2ea030b). Where a page is given, it was also checked in the report itself; literature was checked against arXiv and Crossref. Suggested changes are in bold.

New results (unrefereed preprints with full proofs, verification scripts and independent referee checks)

• OWR-16164-019 → solved (no). Sportiello's conjecture B_λ ≥ A_λ (OWR 23/2018, pp. 1455–1457) fails for the band λ = {(x,y) ∈ [7]² : −3 ≤ y−x ≤ 4}, where A_λ = 536 and B_λ = 515. Every digitally convex shape of side ≤ 6 satisfies the inequality; among the 5,693,968 shapes of side 7, only this band and its transpose violate it. (The record attaches the red and blue crosses to the opposite colours; that swap is a bijection on colourings and does not change B_λ.) Paper: doi:10.5281/zenodo.23006715 (page).

• OWR-1782-009 and OWR-1386-013 (the same conjecture) → false as stated. Both ask that minimum codegree ⌊(n−k+3)/2⌋ force a tight Hamiltonian cycle for all n: for n ≥ k+1 ≥ 4 in OWR 01/2008 (p. 46), and with no range of n in OWR 48/2006 (p. 2928). This all-n form is Conjecture 1.1 of Rödl–Ruciński–Szemerédi, Adv. Math. 227 (2011), who attribute it to Katona–Kierstead. It fails for (k,n) = (3,7), (3,9), (4,8), (5,9) and (5,10). The smallest counterexample is an apex joined to all 15 pairs of a 6-set W, plus the ten faces of the hemi-icosahedron on W. Its pair-degrees are 3 and 5. But in a cyclic order (apex, w₁, …, w₆) the disjoint windows w₁w₂w₃ and w₄w₅w₆ would both have to be faces, and no two faces are disjoint. The (5,10) example has codegree 4 = (n−k+3)/2, so the version without the floor fails too. The large-n statement is not affected: RRS proved it for k = 3, and Letzter–Lang–Ranganathan–Sanhueza-Matamala have announced it for all k ≥ 3, as reported in arXiv:2609.08613. Suggested status: "false as stated (small counterexamples); the large-n form is proved for k = 3 and announced for all k". Also:

  • OWR-1386-013 should say "tight" Hamiltonian cycle, as its source defines it; under a Berge reading these hypergraphs do have Hamiltonian cycles;
  • mark the two records as duplicates;
  • the literature DOIs on OWR-1782-009 concern other thresholds (10.1016/j.jcta.2015.01.004: Hamilton ℓ-cycles with ℓ < k/2; 10.1112/jlms.12561: minimum d-degree conditions). RRS 2011 and arXiv:2609.08613 are the relevant references.

  Paper: doi:10.5281/zenodo.23006718 (page).

• OWR-14299577-018 → solved (yes, both questions). The problem was proposed by C. Bernert and N. Arala Santos, in the problem session compiled by T. F. Bloom (OWR 51/2025, p. 2756), so proposed_by can be filled in. Let A ⊂ {−n,…,n}∖{0} contain exactly one of k and −k for every k ≤ n. Then at most two elements of [1,n] are missing from A − A. This is sharp: {1,…,a} ∪ {−(a+1),…,−n} misses exactly a and a+1 whenever n/2 ≤ a ≤ n−1. For every B ⊆ [1,n], the number of pairs (a,b) ∈ A² with a − b ∈ B is at least ⌊(|B|−1)²/4⌋, and this is attained for every |B| ≤ ⌊2n/3⌋+1. So for |B| ≥ εn the count is at least (1/4 − o(1))ε²n². The key step is that the representation counts r(d) of any set S of differences of one parity satisfy Σ_{d∈S} r(d) ≥ C(|S|,2), by a double count of the positions where the sign pattern repeats at distance d. The record's original_statement is garbled: it drops the set-up sentence and splices in two sentences from the preceding problem (Assing). Paper: doi:10.5281/zenodo.23006720 (page).

Stale statuses

• OWR-16160-016 → solved as stated (classical). Valette asks whether the congruence subgroups of G ⊂ SL_N(ℤ) depend on the embedding (OWR 19/2018, p. 1151). In general they do. For example, F₂ embeds as ⟨(1 2; 0 1), (1 0; 2 1)⟩ and as ⟨(1 3; 0 1), (1 0; 3 1)⟩. The level-2 subgroup of the second embedding contains no congruence subgroup of the first, and the level-3 subgroup of the first contains none of the second, so the two congruence topologies are incomparable. Classical instances go back to Serre: SLₙ(ℤ) has congruence subgroups whose images under the adjoint map are not congruence subgroups (Lubotzky–Venkataramana, Algebra Number Theory 13 (2019), Prop. 2.1). For the groups of the talk, Z² ⋊_A Z, the answer is the opposite, and the same holds for every solvable G. Solvable groups have the congruence subgroup property (Chahal, Nagoya Math. J. 79 (1980)), and solvable subgroups of GLₙ(ℤ) are polycyclic, so every embedding induces the profinite topology (LV, §1.1). A scope note would help.
• OWR-1265-006 → solved (yes). Olsson's containment question (OWR 15/2006, p. 913) is the Olsson–Stanton conjecture. Vandehey proved it (arXiv:0809.2134, 2008), and Fayers gave another proof (JCTA 118 (2011)).
• OWR-1536-011 → solved (no, both parts). Knox (arXiv:1212.3345) gives a hypergraph on which Breaker, moving second, wins Maker–Breaker, yet Chooser wins Chooser–Picker. Knox notes that the Picker–Chooser part is equivalent to it; the equivalence comes from the transversal-hypergraph duality stated in the source (OWR 20/2007, p. 1095). So the transversal hypergraph of his example refutes the Picker–Chooser part too.
• OWR-4425-020 (duplicate -021) → solved (yes). Shallit's Conjecture 48 (OWR 37/2010, p. 2236) is Theorem 18 of Cassaigne–Currie–Schaeffer–Shallit, J. ACM 61 (2014), for exactly this morphism.
• OWR-2090-021 → partially solved. Adiprasito–Björner (arXiv:1401.7301, Thm 2.1) prove the Mikhalkin–Ziegler conjecture from this problem session:
  • for a generic weight and t ≤ min{0, total weight}, the proper flats of weight > t form a homotopy Cohen–Macaulay poset, hence an (r−3)-connected one;
  • the "non-negative" version follows by a small perturbation;
  • they credit rank 3 to Pinchasi–Ziegler (personal communication, 2008);
  • shellability is still open (their Open Problem 3.2).
• OWR-12481-012 → solved (no). When Friedgut re-posed it for fixed t and large n, the report recorded: "This turns out to be false; a counterexample was found by Gábor Tardos" (OWR 22/2016, p. 1217). The question as posed here already fails for n = 4, t = 2. Pair σ with σ∘(1 2) if σ maps {1,2} onto {1,2} or {3,4}, and with σ∘(3 4) otherwise. The resulting 12 two-cosets refine none of the 8 partitions of S₄ into 1-cosets.
• OWR-16633-025 → solved (no), over every field. We found no written answer, but a 4-element example settles it: T₀ = F², T₁ = ⟨e₁⟩, T₂ = ⟨e₂⟩, T₃ = ⟨e₁+e₂⟩. Then f(0) = 2, f(1) = f(2) = f(3) = 1, and f(S) = 2 for every other nonempty S. Suppose f = Σ c_j r_j with c_j > 0 and matroid ranks r_j on {0,1,2,3}; the r_j need not even be representable.
  • Every matroid has r(0i) ≥ r(0) and r(ij) ≤ r(i) + r(j). Since f attains equality in both, so does every r_j.
  • So in each r_j, the elements 1, 2 and 3 lie in the closure of 0, which has rank ≤ 1, and at most one of them is a non-loop.
  • Hence r_j(123) = r_j(1) + r_j(2) + r_j(3) for every j, and summing gives f(123) = 3. But f(123) = 2.
  • Over GF(2), 2·r(U₂,₄) is another example. Dougherty–Freiling–Zeger (arXiv:0910.0284, §4) represent it over every field. Its only possible matroid summands are copies of U₂,₄, which is not binary.

Answered in the source itself

• OWR-4791-006 → solved. Fox–Lee–Sudakov prove both conjectures in the abstract itself (OWR 01/2011, pp. 11–12: Thm 2, f(m) = ⌊√(4m+1)⌋ − 1, and Thm 4). The paper is Israel J. Math. 191 (2012). The record's own verification note already says so.
• OWR-16931-001 → solved. The record asks only about sufficiently large n. For that case the source says "We answer this affirmatively for all sufficiently large n" (OWR 19/2019, p. 1158). This is Glock–Joos–Kim–Kühn–Osthus, JEMS 23 (2021).
• OWR-14299518-002 → solved. Alon answers both questions in the abstract itself (OWR 42/2025, pp. 2249–2250): (1) no (Thm 3), (2) yes (Thm 4). These are Erdős problems #664 (disproved) and #732 (proved). The note's "structural characterization" is not part of this record.
• OWR-12872-010 → solved, and one formula needs fixing. Stanley (with F. Liu) proves both of Elkies' conjectures in the same abstract (OWR 12/2014, pp. 696–697); the paper is Ramanujan J. 36 (2015). For n = 2m the count of maximum families is 2^((m−1)(m−2))·(2^m − 1), not ·(2m − 1). A brute-force count gives 28 for n = 6 and 960 for n = 8.

Transcription errors and literal readings

• OWR-14298158-004: Claesson's conjecture is monotonicity in the length n for fixed k: |Av_n^k(1324)| ≤ |Av_{n+1}^k(1324)| (OWR 6/2024, p. 284; Claesson–Jelínek–Steingrímsson, JCTA 119 (2012)). The same correction applies to the Av(1324, 231) part. As written (k → k+1), the statement is false for every n, e.g. |Av_{2,1}| = 1 > 0 = |Av_{2,2}|.
• OWR-17135-030, -031, -032: the source prints M_ii = Σ_{S∋i}|S| (OWR 39/2019, p. 2464). This is a typo for Σ_{S∋i} X_S = deg(i).
  • With that diagonal, det M = |X|·|Y|·τ(G)/∏_{y∈Y} deg y. So Conjecture 5 becomes equivalent to Ehrenborg's Conjecture 4, as the source says.
  • As printed, Conjecture 5 is false. Take X = [3], hang 13 leaves on each vertex of X, and add one vertex joined to all three. Then det M = 850 > 512 = det(diag M). It also fails if the sum runs only over the sets S that occur.
  • With the corrected diagonal, Conjecture 5 is Ehrenborg's conjecture, proved by Ho (arXiv:2603.17997; -030 already cites it).
  • The refinement in -031/-032 is false as literally stated, already at n = 3. There det(diag M) − det M is homogeneous of degree 3 with coefficient −1/4 on X₁₂X₁₃X₂₃. No such polynomial equals Σc_μx^μ + Σc_μν(x^μ − x^ν)² with all c ≥ 0, because the square terms would contribute a nonzero part of even degree. If multipliers x^ρ(x^μ − x^ν)² were intended, the record should say so.
• OWR-14299089-007: as written, the question is trivial: (a_n b_n)² ≥ a_{n−1}a_{n+1}b_{n−1}b_{n+1} for nonnegative sequences. The source asks Brändén–Ferroni–Jochemko's Question 6.1 (Trans. AMS 2026, arXiv:2408.12386). Write Σ p(n)xⁿ = W(p)/(1−x)^(deg p+1). If W(p) and W(q) are log-concave with no internal zeros, is W(pq)?
• OWR-11695867-010: as the source itself says (OWR 57/2022, p. 3274), the case ℓ = 0, Σ f_λ² = n!, is "exactly the Robinson-Schensted-Knuth algorithm". Louf's Open problem 1 is a bijective proof of n!·H_{n,ℓ} = Σ_{λ⊢n} f_λ² C_λ^ℓ for all ℓ. Here H_{n,ℓ} counts ℓ-tuples of transpositions with product 1, and C_λ is the content sum.
• OWR-16164-005: the literal question has a classical answer. Put y_i = 1 − x_i for odd i; each constraint then becomes y_i ≤ y_{i+1} or y_i ≥ y_{i+1}. So the polytope is the order polytope of a fence, a poset whose Hasse diagram is the path 1–2–⋯–n. Its Ehrhart polynomial is Ω(P, t+1) (Stanley, DCG 1 (1986)), so h* is the descent polynomial of its linear extensions (natural labelling). We checked this for all 63 sign sequences with n ≤ 6. Mark solved, or restate if another interpretation was intended.

Duplicates

• Across reports: OWR-12481-012 is the Friedgut half of OWR-12861-020 (OWR 18/2013, p. 1118; OWR 01/2014, p. 81). Splitting OWR-12861-020 would leave there only Diestel's k-block question, which is open.
• New: OWR-14299904-003 repeats -002, which is Weigandt's Conjecture 1 (OWR 2/2026, p. 133); -004 is Conjecture 2.
• Already flagged: the following records are marked as repeats in their own statement_verification, but are still published as open or partially solved. So each of these problems is counted twice. A duplicate status, or unpublishing, would help. The records are OWR-734-010, OWR-1183-007, -012, OWR-4425-019, -021, OWR-4791-016, OWR-4798-022, OWR-11136-011, OWR-14604-015, OWR-16633-022, -024, OWR-16763-026, -028, OWR-17135-032 and OWR-1703876-017.

Merged records

• OWR-1703876-016 (duplicate -017) bundles Problems 6–10 of the OWR 30/2020 problem session (p. 1522), posed by five different people. Splitting would help. Two of its notes need fixing:
  • Problem 10 (Welzl, partial triangulations) is solved (yes) by Kupavskii–Volostnov–Yarovikov, Europ. J. Combin. 108 (2023) (arXiv:2104.05855). -017 lists that arXiv paper under the names Aichholzer–Orden–Schnider.
  • Problem 8 (Steiner, bichromatic triangles) is still open. -016 says a 2026 preprint proves it. In fact Radtke–Keszegh–Lauff (arXiv:2601.20574) prove it only for at most 5 red pseudolines (so for n ≤ 11). In general they prove only that a two-coloured triangle or quadrangle exists.
• OWR-4425-003 bundles Currie's Open problems 2–4 (OWR 37/2010, p. 2206): Restivo–Salemi reachability, the curling-number conjecture and the lexicographically least 5/2-power-free word. Splitting would help.
• OWR-2090-006 bundles Linial's open-ended challenges on Latin squares and the Γ function with one precise conjecture (OWR 44/2008, p. 2496): the maximum rank of a real n×n×n tensor is (1+o(1))n²/2. That conjecture deserves its own record.
• OWR-2090-026: the statement is clean (Problem 9, Barvinok–Samorodnitsky), but original_statement also contains Problem 10 (Welzl, spanning trees versus triangulations). That problem is already OWR-2090-027.

Garbled extracts (all already marked "unrecoverable", but still published as open or partially solved)

• OWR-12861-024: the source itself is ill-posed (OWR 01/2014, p. 83). The matrix has rows indexed by S_n but columns only by {σ : LIS(σ) ≥ n−t}, and it is called both M and A, so its determinant is undefined.
• OWR-9790358-007: the opening of Hakopian's abstract plus its title (OWR 7/2022, p. 405), with no question in it. Its only conjecture, Gasca–Maeztu, is OWR-9790358-001.
• OWR-12697684-002, -003: table-of-contents lines (OWR 1/2023, pp. 9–10). -012: background sentences from Bucić's abstract (p. 42) about the Erdős–Hajnal conjecture, which is -011.
• Also in OWR 1/2023: the "original OWR report" link of OWR-12697684-001, -002, -003, -011 and -012 points to 10.4171/owr/2022/57 (Enumerative Combinatorics). It should be 10.4171/owr/2023/1.
• OWR-14298158-001: a table-of-contents entry (OWR 6/2024, p. 277). -016: the closing remark of an abstract on Bevan's conjecture (p. 299); the conjecture itself is -015.
• OWR-723-001: Beck's four circle-discrepancy questions. The source itself reports them as answered, by Schmidt and by Beck (OWR 13/2004, pp. 678–679). The conjecture that remains is OWR-723-002. Mark solved or remove.

Misattached notes

• OWR-2090-021: the note (parametric assignment, rotation matching) belongs to Rote's Problem 2 of the same session, least-squares matching under rotation (OWR 44/2008, pp. 2546–2547). The relevant literature for this record is Adiprasito–Björner (above).
• OWR-4425-012: the note ("sum-square avoidance", Au–Robertson–Shallit) is about the additive-square problem, Problem 47, which is OWR-4425-018. The record itself is Shallit's Problem 38 on pattern characterisations of α-powers (OWR 37/2010, p. 2231).

— Alper Ferudun

A scoped contribution related to AIM-ANALYSIS-0041 (AIM Problem 1.2, geometry of complete Reinhardt domains with trivial Bergman space):

Finite-Dimensional Lp-Bergman Spaces on Complete Reinhardt Domains — Alper Ferudun (Mercury Software GmbH).

• For every positive rational p, the unweighted Lp-Bergman space of a coordinatewise complete Reinhardt domain in any complex dimension has dimension zero or infinity.
• In C^2, the exact possibilities are {0, infinity} for rational p and {0, 1, infinity} for irrational p.
• An explicit unbounded complete domain with smooth boundary has dimension one for a countable dense set of irrational exponents and dimension zero at every other positive exponent. Its logarithmic image contains no affine line; its bounded holomorphic functions are constant, and nonconstant entire curves lie on coordinate axes.
• For every irrational p and every integer k>=2, a related complete domain in C^3 has exactly k-dimensional Lp-Bergman space.

No pseudoconvexity is assumed. Classical monomial methods and the related multiplier argument of Englis are credited. These are complete scoped theorems and examples, not a full classification resolving the original broad geometry question; the source record should remain partially resolved.

Paper, source and verification report: https://doi.org/10.5281/zenodo.23302183
Readable landing page: https://eulersolve.org/papers/aim-analysis-0041/

The six-page preprint is AI-assisted, self-audited and unrefereed. No independent human review, formal verification or absolute-priority certification is claimed. Exact algebra regression checks support the analytic proofs but are not themselves a proof of the general statements.

Status follow-up 52: one status correction (AMR-043-0005)

• The item was checked against the current dataset (commit 372682f) and its sources. The suggested change is in bold.

Answered in the literature (label → solved)

• AMR-043-0005 → solved (yes); the dataset currently labels it partially solved. F. Ledrappier, Problem 1 of the problem list of the 3rd Pingree Workshop on Dynamical Systems (2010): for the geodesic flow (g_t) of a compact Riemannian manifold of constant negative curvature, is there a probability measure invariant under the time-one map g_1 and not under the flow?
  • Surfaces: A. Quas, T. Soo, Weak mixing suspension flows over shifts of finite type are universal, J. Mod. Dyn. 6 (2012), 427–449 (arXiv:1110.1113), Corollary 4: for the geodesic flow of a compact surface of variable negative curvature there is a measure that is invariant and ergodic for the time-one map and not invariant under the flow. The paper states the question as a problem of F. Ledrappier, F. Rodriguez Hertz and J. Rodriguez Hertz and obtains the corollary from its Theorem 1 (the time-one map is universal) and an ergodic automorphism of small entropy without a square root; Proposition 13 of the appendix (a set minimal for the flow and not for the time-one map) gives a second answer.
  • Dimension ≥ 3: we found no statement in print. The same conclusion follows from D. Burguet, Topological and almost Borel universality for systems with the weak specification property, Ergodic Theory Dynam. Systems 40 (2020), 2098–2115 (arXiv:1901.00666), Corollary 1.1 (a topological system with the almost specification property is universal for ergodic aperiodic systems of smaller entropy), applied to the time-one map, which has the specification property by Bowen's theorem for topologically mixing hyperbolic flows: embed the dyadic odometer; the measure obtained is ergodic for g_1 and has a real eigenfunction with eigenvalue −1, so it is not invariant under g_{1/2}. This deduction is ours.
  • Read: in version 2 of the arXiv paper of Quas and Soo, the statement of the problem, Theorem 1, Corollary 4 with its proof and Proposition 13; the introduction of the arXiv version of Burguet's paper (Theorem 1.2, Corollary 1.1 and the definitions). Not read: the journal versions; Bowen's paper (Amer. J. Math. 94 (1972)).

This is an AI-assisted, self-audited check, not independent human peer review. Corrections are welcome. — Alper Ferudun, Mercury Software GmbH

AIM-ANALYSIS-0056: sharp criteria for a specified neutral Jordan skew-product family

I have posted Sharp Attraction Thresholds for Neutral Jordan Skew Products, an English preprint giving a complete criterion within the family stated in the paper. This is a scoped contribution to AIM Problems on Complex Dynamics 2.3, not a resolution of the general question about degenerate characteristic directions; the broad source record should remain partially solved.

For integer t>=1, the base is g(z)=z-z^(2t+1)+a z^(3t+1)+O(z^(3t+2)); the fiber multiplier is I-i z^t B-c z^(2t) I+R(z), where B has real spectrum and R is a polynomial in B whose scalar coefficients vanish to order 2t+1. The missing intermediate base coefficients and the commuting linear-fiber hypothesis are part of the theorem.

An open local attracting domain exists exactly when Re(c)>max_beta{beta^2/2+beta Im(a)+t(m_beta-1)}, with m_beta the largest Jordan block at beta. First-order attachment to the base axis requires the same strict bound with +1. The paper proves every Jordan-height rate, excludes the equality cases, constructs forward-invariant open domains, and gives equal-spectrum and higher-base-coefficient contrasts. It does not claim a number of maximal basins, nonlinear-fiber or noncommuting extensions, or all-orders formal-curve attachment.

Lapan's related results and Jordan examples, classical shearing/difference-equation asymptotics, and the stronger formal-curve notion are credited. The preprint is AI-assisted, self-audited and unrefereed; there is no independent-review, formal-verification or absolute-priority claim. The source archive includes 5,567 finite exact algebra regressions in both normal and optimized Python; these checks are not a substitute for the analytic proof.

• Source question: http://aimpl.org/scvproblems/2/ (Problem 2.3)
• DOI and files: https://doi.org/10.5281/zenodo.23304667
• Web page: https://eulersolve.org/papers/aim-analysis-0056/

Alper Ferudun, Mercury Software GmbH

AMR-052-0003 — literature correction: joint continuity is false; the fixed-input question is separate.

Bielefeld's original Question 3 (IMS 92/7, printed p. 3) asks both about holding one polynomial fixed and about joint continuity: https://www.math.stonybrook.edu/preprints/ims92-7.pdf

The frozen v1.6.0 research summary says a general joint-continuity theorem remains open. Counterexamples are already known. Buff–Epstein–Koch–Meyer–Pilgrim–Rees–Tan, Questions about Polynomial Matings (2012), Section 2.4, discuss joint discontinuity and separately ask about a fixed-input slice in Question 2.5: https://doi.org/10.5802/afst.1365

A concrete example with an existing limiting mating is Wolf Jung, Quadratic matings and ray connections (2017), Section 3.5, Theorem 3.9: https://arxiv.org/abs/1707.00630. Both polynomial inputs vary. The approximating matings have a critical point mapping to the other critical point, while the mating of the input limits does not, precluding convergence to that map.

Suggested correction: retain a partial status for the combined source question, but state that joint continuity is false in known literature; do not list proving general joint continuity as remaining work. These examples do not resolve the fixed-input question. This is a credited literature correction, not a new result or a new paper from us.

AIM-PHYSICS-0055 — complete planar theorem; spatial part still unresolved

I have published the preprint Constant Normalized Area in the Planar Three-Body Problem (Alper Ferudun, Mercury Software GmbH):

• DOI: https://doi.org/10.5281/zenodo.23306186
• Paper, source and verification report: https://eulersolve.org/papers/aim-physics-0055/
• Original source: https://aimath.org/WWN/varcelest/varcelest.pdf, Problem 18, attributed to Wu-Yi Hsiang.

For arbitrary positive masses, the theorem states that a collision-free noncollinear planar Newtonian three-body motion whose triangle area divided by barycentric moment of inertia is constant on an open time interval must be Lagrange homographic. The collision-free exactly periodic planar motions with constant unsigned ratio are therefore precisely the elliptic Lagrange and Euler families, including circles.

The proof uses the classical mass-Jacobi shape reduction and analytically continues necessary energy and latitude equations to an isolated complex binary branch point. Both possible vanishing orders give nonzero incompatible leading energy coefficients. The reduction and homographic families are credited to the existing literature, and the energy-comparison method is related to Fujiwara–Fukuda–Ozaki–Taniguchi's work on Saari's conjecture. Constant normalized area is not being replaced by their different invariant.

Scope: this addresses the planar component only. Genuinely precessing spatial motions and the source's separate meridian remark remain unresolved here. Please do not mark the whole AIM-PHYSICS-0055 record solved on the basis of this paper.

The five-page PDF, LaTeX source and 26 exact symbolic regression checks are available. The checks support the algebra but are not a formal verification of the analytic proof. This preprint is AI-assisted, self-audited and unrefereed. No independent review or absolute-priority certification is claimed; a bounded literature search is not proof of novelty.

OWR-4990374-015 (Tohăneanu, free arrangements with exponents 1's, 2's and at most one 3): the conjecture holds in every rank; a complete proof

I have released an unrefereed preprint, Free Hyperplane Arrangements with Exponents 1, 2 and at Most One 3 Are Supersolvable: A Proof of a Conjecture of Tohăneanu (Alper Ferudun, Mercury Software GmbH).

• Zenodo (PDF, LaTeX source, programs with recorded outputs, verification report): https://zenodo.org/records/23307000
• DOI: https://doi.org/10.5281/zenodo.23307000

Conjecture. Ş. O. Tohăneanu (Oberwolfach Report 5/2021, p. 284; Conjecture 4.1 of the preprint arXiv:1707.07091v3): every central free hyperplane arrangement, over a field of characteristic zero, whose exponents are 1's, 2's and at most one 3 is supersolvable. (The exponents are the degrees of a basis of the module of logarithmic derivations; the Euler derivation has degree 1.)

Result. The conjecture holds in every rank, over every field of characteristic zero, for all central arrangements, including reducible and non-essential ones (Theorem 1.1). The proof is complete and uses no computation. Its core does not mention freeness and holds over every field: an essential, irreducible, formal arrangement of rank k with 2k hyperplanes, with every codimension-two flat in at most four hyperplanes and with the sum of C(m_Z − 1, 2) over these flats equal to k + 1, is supersolvable (Theorem 1.2). With two exponents 3 the statement is false: the non-Fano arrangement (exponents (1,3,3)) and an arrangement of nine hyperplanes of rank four (exponents (1,2,3,3)) are free and not supersolvable.

Credit. The conjecture and the strategy of the proof are Tohăneanu's (the preprint and the Oberwolfach abstract): free arrangements are formal (Yuzvinsky's theorem), two hyperplanes which lie in a single dependent triple give a modular coatom, induction on the rank, and the counts n = 2k and u + 3v = k + 1. The cases of exponents 1 and 2 only and of a quadruple point (a codimension-two flat in four hyperplanes) follow from a theorem of M. DiPasquale (Math. Ann. 385 (2023), Proposition 6.1 with Corollary 4.10) and are proved again; rank three is in Tohăneanu, Discrete Math. 339 (2016). The proof that free arrangements are formal follows Brandt and Terao (1994). What the note adds, to our knowledge and relative to the literature we found, is the case without a quadruple point in rank at least 4, and therefore the conjecture in general. A preprint of W. Liang and S. Wang (arXiv:2608.01331, August 2026) treats arrangements with a regular underlying matroid; it does not contain the conjecture.

What stays open. Nothing of the conjecture as posed. Not claimed: fields of positive characteristic (only a remark: the proof goes through over every field over which Saito's criterion holds), and other exponents (for exponents 1, 2 and one 4 the note makes no statement).

Note on the record: its statement does not name the field (characteristic zero in the source), and the cases it lists as verified are those of the preprint arXiv:1707.07091, which its author withdrew on 16 January 2022.

Suggested status: solved (the dataset currently labels the record open). The book of Orlik and Terao was not accessible to us and was not read; it is cited through papers which we read. Novelty is not certified.

Three independent AI-assisted verification runs re-checked the proofs line by line, compared the cited theorems with their sources and tested the statements with separately written programs (exact enumerations over the rationals and over finite fields; no counterexample). Our literature search (arXiv, Crossref, zbMATH, OpenAlex, web) found no proof and no counterexample of the conjecture. This is AI-assisted, self-audited and unrefereed work, not independent human peer review or formal certification. No absolute-priority claim is made. Corrections and prior-work pointers are welcome. — Alper Ferudun, Mercury Software GmbH

Scoped preprint update for AIM-ALGEBRAIC_GEOMETRY-0211 (AIM Algebraic Vision, Problem 5.3):

A Pivot-Independent Toric Model for Framed Carlsson-Weinshall Duality

For an ordered anchor simplex in projective d-space and n >= 2 further marks off the anchor faces, the paper constructs the minimal common normal projective toric model dominating the product-permutohedral compactifications for every choice of pivot. Its fan is the rectangle-character arrangement. It is smooth exactly when d = 1 or n = 2; for d >= 2 and n >= 3 an explicit four-dimensional five-ray cone proves that it is not Q-factorial. Inversion is regular, and in dimension three it induces CW isomorphisms on the reduced-measurement graph closures and their normalizations.

Scope: this is a complete theorem for that specified anchor-framed model, NOT a full solution of the open-ended AIM moduli-space question, NOT a stable compactification of unframed camera moduli, and NOT a claim that the measurement map is regular everywhere on the toric model. The original dataset entry should remain partially resolved under this update.

Classical CW duality, rational-quotient descriptions, permutohedral inversion and standard toric machinery are explicitly credited, including related prior Chow-quotient singularity examples. Exact-arithmetic regression material is included; it is not formal verification. The preprint is AI-assisted, self-audited and unrefereed, with no absolute-priority claim.

DOI and archived files: https://doi.org/10.5281/zenodo.23308121
Paper page and files: https://eulersolve.org/papers/aim-algebraic-geometry-0211/
Original problem: http://aimpl.org/algvision/5/