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Nonexistence of asymptotically self-similar singularities in the Euler and the Navier-Stokes equations

Analysis of PDEs · Submitted 11 Apr 2006 · 35 references

Pith's verdict: The Navier-Stokes half is a genuinely new and clean localized result; the Euler half leans on an unstated theorem from the author's own preprint, and that gap should be fixed before publication.

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arXiv IDmath/0604234 (version 8)
Pith IDA45C5DL7, Pith's permanent record of this paper and its review
CitationDongho Chae. "Nonexistence of asymptotically self-similar singularities in the Euler and the Navier-Stokes equations." arXiv:math/0604234 (2006). https://pith.science/paper/A45C5DL7
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The paper

The paper claims

Self-similar blow-up ruled out in 3D Euler and Navier-Stokes

The reading

This paper argues that a specific route to finite-time singularity—whereby a smooth solution approaches a self-similar profile as the singularity time is approached—cannot occur for the 3D incompressible Euler or Navier-Stokes equations. If the Euler vorticity converges to a self-similar vorticity profile in the critical Besov space $\dot B^0_{\infty,1}$, then the profile must be zero, and the solution extends smoothly past the suspected time. If the Navier-Stokes velocity converges to a self-similar velocity profile in $L^q$ on balls shrinking like $\sqrt{T-t}$, the profile must be zero and the solution is Hölder continuous near the point. Because self-similar profiles are the standard ansatz in singularity searches, ruling them out redirects the blow-up question to non-self-similar or weaker-convergence scenarios.

What carries the argument

The argument runs through similarity variables, $y=x/(T-t)^{1/(\alpha+1)}$ and $s=\frac{1}{\alpha+1}\log(T/(T-t))$ for Euler, and the analogous $\sqrt{T-t}$ variables for Navier-Stokes. In these variables convergence to a profile becomes convergence as $s\to\infty$, and a weak-limit passage using divergence-free test functions shows the limit profile solves the stationary Leray system (for Navier-Stokes, $\bar V+(y\cdot\nabla)\bar V+2(\bar V\cdot\nabla)\bar V=-\nabla\bar P+2\Delta\bar V$) or the stationary Euler profile equation (2.9)-(2.10). Known rigidity theorems for these stationary problems give $\bar V=0$ (or $\bar\Omega=0$), and a continuation principle in the same critical spaces pulls the conclusion back to the original variables.

Extended reading notes

Core claim

The central claim is that asymptotically self-similar singularities are impossible under the paper's convergence hypotheses. For Euler (Theorem 1.2), if a solution $v\in C([0,T);B^1_{\infty,1}(\mathbb{R}^3))$ satisfies $\lim_{t\nearrow T}(T-t)\|\omega(\cdot,t)-\frac{1}{T-t}\bar\Omega\big(\frac{\cdot}{(T-t)^{1/(\alpha+1)}}\big)\|_{\dot B^0_{\infty,1}}=0$ for some $\alpha>-1$ and $\bar\Omega$ in the stated $L^q$ class, then $\bar\Omega=0$ and the solution continues to $C([0,T+\delta);B^1_{\infty,1}(\mathbb{R}^3))$ for some $\delta>0$. For Navier-Stokes (Theorems 1.4 and 1.5), if the velocity converges to $\frac{1}{\sqrt{T-t}}\bar V(\cdot/\sqrt{T-t})$ either globally in $L^p$, $p\in[3,\infty)$, or locally on shrinking balls in $L^q$, $q\in[2,\infty)$, then $\bar V=0$; in the local case $v$ is Hölder continuous near $(z,T)$.

Load-bearing premise

For the Euler result, everything hangs on an earlier theorem, not proved here, that the only stationary self-similar Euler profile with vorticity in the relevant Besov and $L^q$ classes is the zero profile; for the Navier-Stokes side, the corresponding load-bearing premise is the known vanishing of Leray self-similar profiles in $L^p$, $p\ge 3$.

Editorial extensions

If this is right

  • For 3D Navier-Stokes, no singularity can form at a point where the velocity converges, on parabolically shrinking balls, to a nonzero self-similar profile in $L^q$ with $q\in[2,\infty)$.
  • For 3D Euler, if the vorticity converges in the critical Besov space $\dot B^0_{\infty,1}$ to a self-similar profile, that profile must be zero and the solution extends smoothly beyond the suspected singularity time.
  • The local version covers convergence with $q\in[2,3)$, which was outside earlier global $L^q$ results; the conclusion is Hölder continuity near the point, not merely extension.
  • Under any of these convergence assumptions, finite-time blow-up cannot be asymptotically self-similar; possible singularities would have to fail the convergence assumptions or take a non-self-similar form.
  • The continuation principles also reproduce the standard lower blow-up rate bounds: $\|\omega(t)\|_{\dot B^0_{\infty,1}}\gtrsim (T-t)^{-1}$ for Euler and $\|v(t)\|_{L^p}\gtrsim (T-t)^{-(p-3)/(2p)}$ for Navier-Stokes.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A numerical blow-up candidate that converges to a self-similar profile only pointwise or in $L^p$ with $p<2$ would not be covered by these theorems; one testable reading is that any genuine counterexample must converge in a weaker topology than the critical Besov or local $L^q$ norms used here.
  • The same weak-limit-to-stationary-profile strategy should transfer to other scale-invariant PDEs whose stationary solutions are known to be rigid, giving a general recipe for excluding asymptotically self-similar blow-up.
  • The local $L^q$ result for $q\in[2,3)$ may combine with partial regularity theory to constrain the singular set: at any actual singular point, the local convergence used in (1.6) must fail in a quantitative way.
Original abstract

In this paper we rule out the possibility of asymptotically self-similar singularities for both of the 3D Euler and the 3D Navier-Stokes equations. The notion means that the local in time classical solutions of the equations develop self-similar profiles as $t$ goes to the possible time of singularity $T$. For the Euler equations we consider the case where the vorticity converges to the corresponding self-similar voriticity profile in the sense of the critical Besov space norm, $\dot{B}^0_{1, \infty}(\Bbb R^3)$. For the Navier-Stokes equations the convergence of the velocity to the self-similar singularity is in $L^q(B(z,r))$ for some $q\in [2, \infty)$, where the ball of radius $r$ is shrinking toward a possible singularity point $z$ at the order of $\sqrt{T-t}$ as $t$ approaches to $T$. In the $L^q (\Bbb R^3)$ convergence case with $q\in [3, \infty)$ we present a simple alternative proof of the similar result in \cite{hou}.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 4,606 input tokens.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.26 · human participants 0.01 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.25 · compares with prior results 0.92 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v8. Results and the main claim are underlined; .

In this paper we rule out the possibility of asymptotically self-similar singularities for both of the 3D Euler and the 3D Navier-Stokes equations. The notion means that the local in time classical solutions of the equations develop self-similar profiles as $t$ goes to the possible time of singularity $T$. For the Euler equations we consider the case where the vorticity converges to the corresponding self-similar voriticity profile in the sense of the critical Besov space norm, $\dot{B}^0_{1, \infty}(\Bbb R^3)$. For the Navier-Stokes equations the convergence of the velocity to the self-similar singularity is in $L^q(B(z,r))$ for some $q\in [2, \infty)$, where the ball of radius $r$ is shrinking toward a possible singularity point $z$ at the order of $\sqrt{T-t}$ as $t$ approaches to $T$. In the $L^q (\Bbb R^3)$ convergence case with $q\in [3, \infty)$ we present a simple alternative proof of the similar result in \cite{hou}.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 In this paper we rule out the possibility of asymptotically self-similar singularities for both of the 3D Euler and the 3D Navier-Stokes equations. result 0.91 0.95 0.98 asserted 1.00
s1 The notion means that the local in time classical solutions of the equations develop self-similar profiles as $t$ goes to the possible time of singularity $T$. background 0.89 0.09 0.03 asserted 0.94
s2 For the Euler equations we consider the case where the vorticity converges to the corresponding self-similar voriticity profile in the sense of the critical Besov space norm, $\dot{B}^0_{1, \infty}(\Bbb R^3)$. method 0.56 0.78 0.04 asserted 0.92
s3 For the Navier-Stokes equations the convergence of the velocity to the self-similar singularity is in $L^q(B(z,r))$ for some $q\in [2, \infty)$, where the ball of radius $r$ is shrinking toward a possible singularity point $z$ at the order of $\sqrt{T-t}$ as $t$ approaches to $T$. method 0.54 0.78 0.04 asserted 0.95
s4 In the $L^q (\Bbb R^3)$ convergence case with $q\in [3, \infty)$ we present a simple alternative proof of the similar result in \cite{hou}. contribution 0.82 0.87 0.03 asserted 1.00

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 1.00.

What was examined, and what was not

sources read
  • arXiv listing abstract v8
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
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  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

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Found among the papers closest to this one by title and main claim. Pith's classifier compared each pair's main results and a second model family confirmed the relation; checked against two further families, shown conflicts agreed 118 times in 120 and shown same results 218 times in 239. The quoted sentence is the other paper's main claim.

States a conflicting result 1 paper

Discussion

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