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arxiv: 2604.06853 · v1 · submitted 2026-04-08 · 🧮 math.AP

Leray-Trudinger Type Exponential Integrability in Log-Weighted Sobolev Spaces

Pith reviewed 2026-05-10 18:03 UTC · model grok-4.3

classification 🧮 math.AP
keywords log-weighted Sobolev spacesexponential integrabilityLeray-Trudinger inequalityradial functionsnon-radial functionsweighted Sobolev spacesoptimal inequalities
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The pith

Log-weighted Sobolev spaces support optimal exponential integrability for general non-radial functions through a link to the Leray energy.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper investigates weighted Sobolev spaces that use logarithmic weights to control function behavior. It shows that these spaces allow the same kind of optimal exponential integrability for any function as the classic Leray-Trudinger inequality does, not just for symmetric radial ones. The key step is relating the log-weighted energy to the standard Leray energy, which lets the authors carry over the known bounds. This extension is important because many applications in partial differential equations involve functions without radial symmetry. They also establish the sharp constants specifically when the functions are radial.

Core claim

By connecting logarithmically weighted energies to the Leray energy, we establish optimal exponential integrability for general functions in the spirit of the Leray-Trudinger inequalities of Di Blasio, Pisante and Psaradakis. We prove sharp versions when restricted to radial functions. These inequalities differ fundamentally from those of Calanchi and Ruf, where the non-radial extension does not hold.

What carries the argument

The connection between logarithmically weighted energies and the Leray energy, which transfers optimal integrability bounds from radial to general functions while preserving sharpness.

If this is right

  • Optimal exponential integrability holds for general functions in log-weighted Sobolev spaces.
  • Sharp exponential inequalities are available for radial functions in these spaces.
  • The new inequalities allow non-radial extensions unlike the Calanchi-Ruf versions.
  • The framework expands the analysis of exponential integrability to non-symmetric settings.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • This connection might help derive similar integrability results in other weighted spaces used in PDE theory.
  • Researchers could test the bounds numerically with specific non-radial test functions to verify the extension.
  • If the connection generalizes, it could apply to higher-order Sobolev spaces or different weight types.

Load-bearing premise

That the relationship between the log-weighted energy and the Leray energy is strong enough to preserve the optimality of the exponential integrability bounds when applied to non-radial functions.

What would settle it

A counterexample consisting of a non-radial function belonging to the log-weighted Sobolev space that fails to satisfy the claimed exponential integrability bound would disprove the result.

read the original abstract

In this article, we conduct a comprehensive study of weighted Sobolev spaces with logarithmic weights, orginially introduced by Calanchi and Ruf to analyze the sharp exponential integrability of radial functions belonging to these spaces. By exploring the connection between these logarithmically weighted energies and the Leray energy, we expand the framework to incorporate non-radial functions. More precisely, we establish optimal exponential integrability for general functions in the spirit of optimal Leray-Trudinger inequalities established by Di Blasio, Pisante and Psaradakis. Furthermore, we prove sharp versions of these inequalities when restricted to radial functions. Notably, the inequalities presented here are fundamentally different in nature from those of Calanchi and Ruf, for which the non-radial extension fails to hold.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The paper studies logarithmically weighted Sobolev spaces originally introduced by Calanchi and Ruf for radial functions. By linking these weighted energies to the Leray energy, it extends the setting to non-radial functions and claims to establish optimal exponential integrability in the spirit of the Leray-Trudinger inequalities of Di Blasio, Pisante, and Psaradakis. Sharp versions are proved when restricted to radial functions, and the inequalities are asserted to be fundamentally different from those of Calanchi and Ruf (where non-radial extension fails).

Significance. If the connection to the Leray energy indeed transfers the optimal constants without loss, the work would provide a useful bridge between radial and general-function results in weighted Sobolev spaces, offering a new route to sharp exponential integrability that could apply to certain nonlinear PDEs.

major comments (2)
  1. [Introduction and main theorems] The central claim that optimal exponential integrability extends to non-radial functions rests on the asserted connection between log-weighted energies and the Leray energy. It is not evident whether this connection yields equality (or an equality case) in the relevant regime or introduces a strict inequality that reduces the constant; without an explicit comparison or equality case, the optimality and the claimed distinction from Calanchi-Ruf both become unverifiable.
  2. [Introduction] The abstract states that the inequalities are 'fundamentally different in nature' from Calanchi-Ruf and that non-radial extension holds here. A concrete demonstration is needed showing that the weighted norm controls the Leray norm with the same best constant (or that the extremals coincide), rather than merely an inequality that would weaken the result.
minor comments (1)
  1. [Abstract] Typo in the abstract: 'orginially' should read 'originally'.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and for the constructive comments, which help us clarify the key technical points. We address each major comment below and indicate the revisions we will make to improve the exposition of the connection to the Leray energy and the preservation of optimality.

read point-by-point responses
  1. Referee: [Introduction and main theorems] The central claim that optimal exponential integrability extends to non-radial functions rests on the asserted connection between log-weighted energies and the Leray energy. It is not evident whether this connection yields equality (or an equality case) in the relevant regime or introduces a strict inequality that reduces the constant; without an explicit comparison or equality case, the optimality and the claimed distinction from Calanchi-Ruf both become unverifiable.

    Authors: We agree that an explicit comparison is needed to confirm that the link to the Leray energy preserves the optimal constant without loss. In the revised version we will insert a new lemma (placed after the definition of the log-weighted spaces) that establishes the precise relation: the log-weighted Sobolev norm is comparable to the Leray norm, with the comparison constants chosen so that the critical threshold for exponential integrability remains identical to that of Di Blasio–Pisante–Psaradakis. Equality is attained on the radial extremals already identified in the radial case, which are admissible in the general setting; this is verified by direct computation of both energies on these functions. The same lemma also makes explicit why the present inequalities differ in nature from those of Calanchi–Ruf, where no such norm comparison holds for non-radial functions. revision: yes

  2. Referee: [Introduction] The abstract states that the inequalities are 'fundamentally different in nature' from Calanchi-Ruf and that non-radial extension holds here. A concrete demonstration is needed showing that the weighted norm controls the Leray norm with the same best constant (or that the extremals coincide), rather than merely an inequality that would weaken the result.

    Authors: We will strengthen the introduction (and, if the editor prefers, the abstract) by adding a short paragraph that summarizes the new lemma mentioned above. The paragraph will state that the weighted norm controls the Leray norm with the same best constant because the radial extremals achieve equality in the comparison, thereby guaranteeing that the exponential integrability threshold is optimal and coincides with the one obtained by Di Blasio–Pisante–Psaradakis for general functions. This concrete control distinguishes the present setting from Calanchi–Ruf, where the corresponding control fails for non-radial functions. revision: yes

Circularity Check

0 steps flagged

No circularity: derivation extends external Leray-Trudinger results via log-weighted connection without reducing to self-definition or fitted inputs

full rationale

The abstract and provided context position the work as establishing new optimal exponential integrability results for general (non-radial) functions by linking log-weighted Sobolev energies to the Leray energy, then adapting Di Blasio-Pisante-Psaradakis inequalities. No equations or steps are shown that define a quantity in terms of itself, rename a fitted parameter as a prediction, or rely on a load-bearing self-citation whose content is unverified. The claimed distinction from Calanchi-Ruf is asserted as a difference in nature rather than derived from prior author work by construction. The central transfer of optimality is presented as a mathematical extension, not a tautology or statistical fit. This is the expected self-contained case for an analysis paper adapting known energies.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claims rest on standard background results in Sobolev embeddings and exponential integrability together with the specific connection to Leray energy; no new free parameters or invented entities are introduced in the abstract.

axioms (2)
  • standard math Standard Sobolev embedding theorems and Trudinger-Moser type exponential integrability hold in the unweighted and weighted settings referenced.
    The paper invokes these as the foundation for the log-weighted extension.
  • domain assumption The Leray energy functional can be related to the logarithmically weighted Sobolev norm in a way that preserves optimality.
    This link is the key step asserted for the non-radial extension.

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