REVIEW 3 major objections 5 minor 16 references
P\'{o}lya's conjecture on $\mathbb{S}^1 \times \R$
T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash
Pith's one-line read This paper proves that on the cylindrical strip $\mathbb{S}^1 \times I_h$, Pólya's conjecture holds exactly for three explicit ranges of $h$, with the only failures at the 8th and 13th eigenvalues.
desk verdict A genuinely new if-and-only-if result for Pólya's conjecture on cylindrical strips, built on sound lattice counting; the proof rests on one unproved convexity claim and an uncerified computer search, both fixable in revision. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The proof reduces Pólya's conjecture to an integer lattice-point count. Eigenvalues of $C_h$ are $m^2 + n^2\pi^2/h^2$ with $m\in\mathbb{Z}$, $n\in\mathbb{N}$, so the counting function $N(\lambda)$ counts lattice points in an ellipse; the conjecture is $N(\lambda) \le \lambda h/2$. Two geometric estimates bound the defect $R(\lambda)=N(\lambda)-\lambda h/2$ by expressions with negative leading terms, giving thresholds $\sqrt\lambda \ge 20$ on the remaining range. This reduces the open question to a bounded set $\lambda<400$, $k\le 1019$, where the paper defines $k$-intervals $I^k_{m,n}=\{h : k > m^2h/2 + n^2\pi^2/(2h)\}$; a nonempty intersection of $k$ such intervals is exactly a value of $h$ where $\lambda_k < 2k/h$. An exact computational search over these intersections returns precisely the two intervals of failure.
What would settle it
Recompute the $k$-interval intersections with exact arithmetic for every $k \le 1019$ using the paper's Appendix A algorithm; if any nonempty intersection beyond the two reported appears, Theorem A is false. Separately, check whether $F(h) = \frac{8}{27}\left(\frac{h/\pi + \sqrt{\pi/h}}{\sqrt{(h/\pi)^2+1} - h/\pi}\right)^2$ is convex on $\left(\frac{1}{9}(9-2\sqrt6)\pi, \pi^2/2\right]$ and whether its endpoint values are both below 20; a point with $F(h)\ge 20$ would invalidate the reduction to $k\le 1019$.
Extended reading notes
Core claim
The central claim is a complete characterization (Theorem A). For $C_h = \mathbb{S}^1 \times I_h$, Pólya's conjecture holds if and only if $h$ lies in $(0, 8-\sqrt{64-4\pi^2}] \cup [2+\sqrt{4-\pi^2/4},\, 13-\sqrt{169-9\pi^2}] \cup [\tfrac{13}{4}+\sqrt{\tfrac{169}{16}-\pi^2},\, \tfrac{\pi^2}{2}]$; the two complementary intervals inside $(0,\pi^2/2)$ are the only failures, caused by $\lambda_8$ and $\lambda_{13}$ respectively. For $h>\pi^2/2$ the first eigenvalue violates the bound. The same characterization transfers to areas: an isoperimetric domain on the infinite cylinder satisfies Pólya's conjecture exactly when its area lies in the three corresponding intervals ending at $\pi^3$ (Corollary B), and the Li-Yau averaged inequalities hold for all $k$ if and only if $h \in (0,\pi^2]$ (Corollary C).
Load-bearing premise
The exhaustive search over $k \le 1019$ rests on the claim that the function $F(h)$ bounding the eigenvalue defect is convex on the remaining interval, so its maximum sits at an endpoint and stays below 20; if convexity or that endpoint value fails, failures at larger eigenvalues could lie outside the searched range.
Editorial extensions
If this is right
- For every $h$ in the three listed intervals, all Dirichlet eigenvalues of $C_h$ satisfy the Pólya bound $\lambda_k \ge 2k/h$.
- For $h$ in either gap, the conjecture fails for exactly one eigenvalue order ($k=8$ in the first gap, $k=13$ in the second), so the obstruction is finitely localized.
- The isoperimetric-domain question on $\mathbb{S}^1\times\mathbb{R}$ is fully answered: a disk or strip of a given area satisfies Pólya's conjecture precisely for the areas in Corollary B, up to area $\pi^3$.
- The Li-Yau averaged inequalities hold for all $k$ on $C_h$ exactly for $h\le \pi^2$, so averages remain true in a range where individual eigenvalues fail.
- For Cartesian products $\mathbb{S}^1 \times I_{h_1} \times \cdots \times I_{h_n}$ with $n\ge 3$, Pólya's conjecture holds whenever the smallest side $h_0$ lies in $(0,\pi^2]$.
Reading between the lines
- The $k$-interval intersection method is a general template: for any product domain whose eigenvalues are quadratic forms in integer indices, the same algorithm converts Pólya's conjecture into a finite exact-arithmetic search, provided one has a uniform large-$\lambda$ bound.
- The two failure gaps occur at eigenvalue orders 8 and 13; a natural question the paper leaves open is whether the pattern of failing orders corresponds to a number-theoretic property of the ellipse's lattice points near the tangent point of slope $-1$ used in the second estimate.
- Conjecture 1.1 predicts small-area domains on the cylinder all satisfy Pólya's conjecture; the quantitative candidate $A_0 = 2\pi(8-\sqrt{64-4\pi^2})$ could be tested by computing low eigenvalues for numerically generated small geodesic disks, whose radius is below the $\pi$ range already covered by known ball results.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper studies Pólya's conjecture for the Dirichlet Laplacian on the infinite cylinder S^1 × R, focusing on the two isoperimetric domain families: geodesic disks and cylindrical strips C_h = S^1 × I_h. For strips, Theorem A claims a complete characterization of h for which the conjecture holds, with failure intervals at eigenvalue orders 8 and 13, and Corollary B transfers this to a characterization by area for all isoperimetric domains. Corollary C extends the Li-Yau averaged inequalities to all h ∈ (0, π²]. The proof combines elementary eigenvalue counting, two analytic upper bounds for the counting-function error R(λ), a uniform threshold λ ≥ 400, and a finite computer search over k ≤ 1019; the Li-Yau result uses a second search over k ≤ 130298 and exact checks up to k = 86.
Significance. If fully rigorous, the result is significant: a complete characterization of Pólya's conjecture for a non-Euclidean cylindrical strip is a rare sharp answer, and the appearance of exactly two failure intervals at eigenvalue orders 8 and 13 is striking and non-obvious. The extension of Li-Yau inequalities to the whole range h ≤ π² is also a clean corollary. A strength is that the paper includes the full Mathematica code for the searches and keeps the analytic part mostly self-contained. However, the two load-bearing computational steps are not certified, and one analytic assertion in Proposition 2.5 is stated without proof, so the current version does not yet constitute a fully verified proof of Theorem A.
major comments (3)
- [§2.2.3, Proposition 2.5] The proof of Proposition 2.5 rests entirely on the assertion that the function F(h) = (8/27)·((h/π+√(π/h))/(√((h/π)²+1)−h/π))² is convex on ((1/9)(9−2√6)π, π²/2], so its maximum occurs at an endpoint, together with the assertion that both endpoint values are below 20. No derivative computation, convexity certificate, or endpoint evaluation is supplied. This step is load-bearing: the resulting uniform bound R(λ) ≤ 0 for λ ≥ 400 is what reduces the infinite spectral problem to the finite search k ≤ 1019 in §2.3. Without it, Theorem A's 'if and only if' is unsupported. Please provide a complete proof, for example an explicit formula for F'' and a monotonicity/endpoint argument, or an interval-arithmetic certified bound.
- [§2.3 and Appendix A] The exhaustive search over k ≤ 1019 is described as rigorous, but the implementation relies on Mathematica's NumericalSort to order roughly 2×10^9 algebraic endpoints and then uses floating-point comparisons to count interval intersections. The manuscript gives no error analysis showing that close endpoints are ordered correctly, and the decisive output (the printed intersections for k = 8 and k = 13) is not independently verified. Since this search is the second load-bearing step of Theorem A, the authors should either provide a certified implementation with exact algebraic comparisons or interval arithmetic, or supply a machine-checkable certificate of the search output.
- [§3 and Appendices B–C] The proof of Corollary C for h ∈ (π²/2, π²] similarly depends on a computed search over k ≤ 130298 and on the numerical identification of eigenvalue orders 7, 10, 77, and 86, followed by exact verification only up to k = 86. The text says 'running it confirms' the remaining inequalities, but the output is not shown, and the code again uses NumericalSort without error bounds. To make the Li-Yau characterization fully rigorous, the search should be certified and the relevant output reported.
minor comments (5)
- [§2.3.1, Lemma 2.6] The phrase 'h is in at least k k-intervals' should explicitly state that these intervals are counted with multiplicity from the lattice-point pairs (m,n). The proof is correct with this multiplicity convention, but the wording is easy to misread.
- [§2.2.3] The sentence 'the second estimate given in Proposition 2.3 is convex in h' is imprecise: convexity is claimed for F(h), not for the estimate itself. Clarify the wording.
- [§3] The statement that the right-hand side of the displayed expression is increasing in h on (π²/2, π²] is used to reduce the verification to the endpoint h = π². A short derivative computation would make this step transparent.
- [§4.1, Theorem 4.1] The value R1 = 3.76085 is obtained by solving an equation numerically, but no rigorous verification is given that the numerator is already positive at this value. If the theorem is intended as a rigorous statement, provide an interval-arithmetic check or an explicit algebraic inequality.
- [Throughout] There are several typographical errors, including 'necesarilly' (p. 1), 'inequaltiy' (p. 3), 'sastisfied' (p. 3), 'P´oly´a' (p. 13), and 'Appedix' (p. 15); a careful proofreading pass is needed.
Circularity Check
No circularity: Theorem A is established by exact eigenvalue counting, a logical equivalence, and an exhaustive finite search independent of fitted parameters.
full rationale
The derivation is self-contained. The eigenvalues are explicit via equation (2.1), and Pólya's conjecture is restated exactly as R(λ) ≤ 0. The analytic bounds in Propositions 2.2–2.3 and the uniform threshold in Proposition 2.5 come from lattice-point geometry and do not assume the target conclusion. Lemma 2.6 is a direct logical equivalence between λ_k < 2k/h and membership in at least k k-intervals, so the subsequent computer search over k ≤ 1019 enumerates precisely all possible counterexamples in the remaining parameter range; there are no fitted constants, no data-dependent selection, and no parameter tuned to force the answer. The cited works [FS], [F], [FLP], and [FMS] are used only for context and motivation, such as earlier examples of tiling domains and prior product results, not as load-bearing premises for Theorem A. The weakest point is Proposition 2.5's asserted convexity and endpoint-maximum property of F(h), which is not proved in the paper; if that assertion were false, the cutoff λ ≥ 400 and the finite search could miss counterexamples. That is a rigor or correctness concern, not circularity, because the convexity claim is an independent analytic assertion rather than an equivalent reformulation of the conclusion.
Assumptions & free parameters
assumptions (3)
- standard math Eigenvalues of the Dirichlet Laplacian on S^1×I_h are λ=m^2+n^2π^2/h^2 with m∈Z, n∈N.
- domain assumption Isoperimetric domains on the infinite cylinder S^1×R are geodesic disks or cylindrical strips bounded by two circles.
- ad hoc to paper The function F(h) defined from the second estimate in Proposition 2.3 is convex on the interval ((1/9)(9−2√6)π, π²/2], so its maximum lies at an endpoint and is below 20.
Cite this review
Pith. "Pith review of P\'{o}lya's conjecture on $\mathbb{S}^1 \times \R$." pith.science (2026). https://pith.science/paper/GZDJGERB
@misc{pith2026250604341,
author = {Pith},
title = {Pith review of: P\'olya's conjecture on $\mathbbS^1 \times \R$},
year = {2026},
howpublished = {\url{https://pith.science/paper/GZDJGERB}},
note = {Machine review of arXiv:2506.04341}
}
abstract
We study the area ranges where the two possible isoperimetric domains on the infinite cylinder $\mathbb{S}^{1}\times \R$, namely, geodesic disks and cylindrical strips of the form $\mathbb{S}^1\times [0,h]$, satisfy P\'{o}lya's conjecture. In the former case, we provide an upper bound on the maximum value of the radius for which the conjecture may hold, while in the latter we fully characterise the values of $h$ for which it does hold for these strips. As a consequence, we determine a necessary and sufficient condition for the isoperimetric domain on $\mathbb{S}^{1}\times \R$ corresponding to a given area to satisfy P\'{o}lya's conjecture. In the case of the cylindrical strip, we also provide a necessary and sufficient condition for the Li-Yau inequalities to hold.
Figures
Figures from the paper (2 more)
Reference graph
Works this paper leans on
-
[1]
P. B\' e rard and G. Besson, Spectres et groupes cristallographiques. II. Domaines spheriques, Ann. Inst. Fourier (Grenoble) 30 (1980), 237--248
work page 1980
-
[2]
D.\ Buoso, P. Luzzini, L. Provenzano and J. Stubbe, Semiclassical estimates for eigenvalue means of Laplacians on spheres, J. Geom. Anal. 33 :280 (2023)
work page 2023
-
[3]
N. Filonov, M. Levitin, I. Polterovich and D. A. Sher, P\' o lya's conjecture for Euclidean balls, Invent. Math. 234 (2023), 129--169
work page 2023
-
[4]
Freitas, Upper and lower bounds for the first Dirichlet eigenvalue of a triangle, Proc
P. Freitas, Upper and lower bounds for the first Dirichlet eigenvalue of a triangle, Proc. Amer. Math. Soc. 134 (2006), 2083--2089
work page 2006
-
[5]
P. Freitas, J. Lagac\' e and J. Payette, Optimal unions of scaled copies of domains and P\'olya's conjecture, Ark. Math. 59 (2021),11--51
work page 2021
-
[6]
P. Freitas, J. Mao and I. Salavessa, P\' o lya-type inequalities on spheres and hemispheres, Ann.\ Inst. Fourier (Grenoble) (to appear), DOI:10.5802/aif.3657
-
[7]
Math.\ Phys.\ 64, 121503 (2023) DOI:10.1063/5.0161050
P.\ Freitas and I.\ Salavessa, Families of non-tiling domains satisfying P\' o lya's conjecture, J. Math.\ Phys.\ 64, 121503 (2023) DOI:10.1063/5.0161050
- [8]
Show all 16 references
-
[9]
Hersch, Bounds for eigenvalues of P\' o lya's ``plane covering domains'' by filling a torus or a cylinder, J
J. Hersch, Bounds for eigenvalues of P\' o lya's ``plane covering domains'' by filling a torus or a cylinder, J. d'Anal. Math. 30 (1976), 265--270
1976
-
[10]
Howards, M
H. Howards, M. Hutchings, and F. Morgan, The Isoperimetric Problem on Surfaces, Amer. Math. Monthly 106 (1999), 430--439. https://doi.org/10.1080/00029890.1999.12005065
1999
-
[11]
Laptev, Dirichlet and Neumann eigenvalue problems on domains in Euclidean space
A. Laptev, Dirichlet and Neumann eigenvalue problems on domains in Euclidean space. J. Funct. Anal. 131 (1997), 531--545
1997
-
[12]
Li and S.-T
P. Li and S.-T. Yau, On the Schr\"odinger equation and the eigenvalue problem. Comm. Math. Phys. 88 (1983), 309--318
1983
-
[13]
Pedrosa, The isoperimetric problem in spherical cylinders, Ann
R. Pedrosa, The isoperimetric problem in spherical cylinders, Ann. Global Anal. Geom. 26 (2004), 333--354
2004
-
[14]
P\' o lya, Mathematics and plausible reasoning: patterns of plausible inference, 2nd Edition, Princeton University Press (1968)
G. P\' o lya, Mathematics and plausible reasoning: patterns of plausible inference, 2nd Edition, Princeton University Press (1968)
1968
-
[15]
P\' o lya, On the eigenvalues of vibrating membranes
G. P\' o lya, On the eigenvalues of vibrating membranes. Proc. London Math. Soc. 11 (1961), 419--433
1961
-
[16]
Urakawa, Lower bounds for the eigenvalues of the fixed vibrating membrane problems, T\^ o hoku Math
H. Urakawa, Lower bounds for the eigenvalues of the fixed vibrating membrane problems, T\^ o hoku Math. J. 36 (1983), 185--189
1983
Reviewed August 7, 2026 · model on record in the stance chip above.
Discussion (0). Sign in to comment.