Bohr type inequality for certain integral operators and Fourier transform on shifted disks
Pith reviewed 2026-05-23 17:41 UTC · model grok-4.3
The pith
Cesàro, Bernardi integral and discrete Fourier operators satisfy sharp Bohr-type inequalities for bounded analytic functions on shifted disks Ω_γ.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
In this paper, we derive the sharp Bohr type inequality for the Cesàro operator, Bernardi integral operator, and discrete Fourier transform acting on the class of bounded analytic functions defined on shifted disks Ω_γ for γ∈[0,1).
What carries the argument
The shifted disks Ω_γ = {z : |z + γ/(1-γ)| < 1/(1-γ)} for γ ∈ [0,1), the domain on which the bounded analytic functions live and to which the three operators are applied.
Load-bearing premise
The bounded analytic functions on Ω_γ form a class on which the Cesàro, Bernardi, and discrete Fourier operators produce functions whose coefficient sums satisfy the stated sharp Bohr-type bounds.
What would settle it
Exhibit one bounded analytic function on a specific Ω_γ whose image under the Cesàro operator (or either of the other two) has coefficient sum exceeding the claimed sharp bound at the relevant radius.
Figures
read the original abstract
In this paper, we derive the sharp Bohr type inequality for the Ces\'aro operator, Bernardi integral operator, and discrete Fourier transform acting on the class of bounded analytic functions defined on shifted disks \beas \Omega_{\gamma}=\left\{z\in\mathbb{C}:\left|z+\frac{\gamma}{1-\gamma}\right|<\frac{1}{1-\gamma}\right\}\quad\text{for}\quad\gamma\in[0,1).\eeas
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript derives sharp Bohr-type inequalities for the Cesàro operator, Bernardi integral operator, and discrete Fourier transform acting on the class of analytic functions f with |f| ≤ 1 on the shifted disks Ω_γ = {z : |z + γ/(1-γ)| < 1/(1-γ)} for γ ∈ [0,1).
Significance. If the sharpness arguments are valid for the restricted class of functions bounded on the full Ω_γ (a proper superset of the unit disk), the results would extend classical Bohr inequalities to a parameterized family of domains and provide explicit constants for these specific operators. The work supplies explicit derivations and sharpness claims for three operators.
major comments (1)
- [proofs of the main theorems (Cesàro, Bernardi, and Fourier cases)] The central sharpness claims (for all three operators) rest on extremal functions that must remain in the class |f|≤1 on all of Ω_γ. Because Ω_γ properly contains the open unit disk and the class is therefore a strict subclass of H^∞(D), standard extremals (Möbius maps or their compositions) used for the unit-disk case may violate |f|≤1 at points of Ω_γ outside D. The manuscript must exhibit or verify admissible extremals that attain the stated constants inside Ω_γ; otherwise the constants are not sharp for the stated class. This issue is load-bearing for every “sharp” statement in the main theorems.
minor comments (2)
- [abstract] The equation defining Ω_γ in the abstract uses display math that could be typeset more cleanly for readability.
- [preliminaries] A brief remark on how the discrete Fourier transform is defined on the coefficient sequence of functions analytic in Ω_γ would clarify the operator for readers.
Simulated Author's Rebuttal
We thank the referee for the careful reading of the manuscript and for highlighting the critical issue with the sharpness arguments. We address the concern point by point below.
read point-by-point responses
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Referee: [proofs of the main theorems (Cesàro, Bernardi, and Fourier cases)] The central sharpness claims (for all three operators) rest on extremal functions that must remain in the class |f|≤1 on all of Ω_γ. Because Ω_γ properly contains the open unit disk and the class is therefore a strict subclass of H^∞(D), standard extremals (Möbius maps or their compositions) used for the unit-disk case may violate |f|≤1 at points of Ω_γ outside D. The manuscript must exhibit or verify admissible extremals that attain the stated constants inside Ω_γ; otherwise the constants are not sharp for the stated class. This issue is load-bearing for every “sharp” statement in the main theorems.
Authors: We agree with the referee that the sharpness claims require extremal functions belonging to the class |f|≤1 on the entire domain Ω_γ, not merely on the unit disk. The manuscript currently invokes standard extremals from the classical unit-disk setting without explicitly verifying that these functions remain bounded by 1 throughout Ω_γ. This is a substantive gap. In the revised version we will either (i) construct or identify admissible extremals that attain the claimed constants while satisfying |f|≤1 on all of Ω_γ, or (ii) qualify the sharpness statements if no such functions exist for the given operators. The revision will cover the Cesàro, Bernardi, and discrete Fourier cases uniformly. revision: yes
Circularity Check
No circularity in derivation chain
full rationale
The abstract claims derivation of sharp Bohr-type inequalities for Cesàro, Bernardi, and discrete Fourier operators on bounded analytic functions over Ω_γ. No equations, coefficient relations, fitted parameters, or self-citations appear in the provided text that reduce any claimed prediction or bound to an input by construction. The domain and class definitions are independent of the target inequalities, and no load-bearing step is shown to collapse via self-definition, renaming, or imported uniqueness. The skeptic concern addresses whether sharpness holds for the restricted class, which is a correctness question outside circularity analysis.
Axiom & Free-Parameter Ledger
Lean theorems connected to this paper
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IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
Theorem 2.1: Cf(ρ) ≤ (1/ρ)log(1/(1−ρ)) for |γ+(1−γ)z|=ρ≤ρ₀ where ρ₀ solves 3(1−ρ)log(1−ρ)+2ρ=0
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IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
Lemma 2.2: |a_n| ≤ (1−γ)^n (1−|a_0|^2) from composition with Φ: D→Ω_γ
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
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