pith. sign in

arxiv: 1907.03433 · v1 · pith:4DY4DJXMnew · submitted 2019-07-08 · 🧮 math.AP · math.FA

Normalized ground states for the fractional nonlinear Schr\"{o}dinger equations

Pith reviewed 2026-05-25 01:23 UTC · model grok-4.3

classification 🧮 math.AP math.FA
keywords fractional Schrödinger equationnormalized ground statesstanding wavesblow-up instabilityglobal existencevariational methodsL2-constrained minimizationChoquard nonlinearity
0
0 comments X

The pith

Normalized ground states exist for the fractional nonlinear Schrödinger equation on the L2-sphere and are strongly unstable by blow-up.

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

The paper proves existence of least-energy normalized solutions to the stationary fractional nonlinear Schrödinger equation on the L2-sphere for both power-type and Choquard-type nonlinearities within specified parameter ranges. These solutions are shown to correspond to standing waves for the time-dependent equation, for which the authors derive a sharp threshold separating global existence from finite-time blow-up. The threshold is then used to conclude that every such normalized ground state standing wave is strongly unstable by blow-up. The argument proceeds by direct minimization of the energy on a specially constructed submanifold of the L2-sphere that restores compactness.

Core claim

By constructing a suitable submanifold of the L2-sphere, we prove the existence of a normalized solution for the stationary equation with least energy in the L2-sphere, which corresponds to a normalized ground state standing wave. Each normalized ground state of the stationary equation coincides with a ground state in the usual sense. We obtain the sharp threshold of global existence and blow-up for the time-dependent equation and show that all normalized ground state standing waves are strongly unstable by blow-up.

What carries the argument

A suitable submanifold of the L2-sphere on which the energy functional attains its infimum.

If this is right

  • At least one normalized ground state standing wave exists for each admissible choice of the nonlinearity and the parameters s, N, p, gamma.
  • The time-dependent fractional Schrödinger equation possesses a sharp threshold on the L2-norm that separates global-in-time solutions from those that blow up in finite time.
  • Every normalized ground state standing wave is strongly unstable by blow-up.
  • Normalized ground states of the constrained problem coincide with unconstrained ground states of the stationary equation.

Where Pith is reading between the lines

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

  • The same constrained minimization could be adapted to other nonlocal dispersive models whose energy lacks compactness on the full L2-sphere.
  • Numerical evolution of initial data exactly at the threshold mass would be expected to exhibit the predicted blow-up in finite time.
  • The coincidence between normalized and unconstrained ground states may simplify the search for explicit profiles in special cases such as s = 1/2.

Load-bearing premise

The given ranges on the exponents p and gamma guarantee the compactness and embedding properties needed for the energy to attain its minimum on the chosen submanifold.

What would settle it

A sequence of functions with fixed L2-norm whose energies approach the claimed infimum but fail to converge strongly in the fractional Sobolev space would falsify the existence of a minimizer.

read the original abstract

In this paper, we study the existence and instability of standing waves with a prescribed $L^2$-norm for the fractional Schr\"{o}dinger equation \begin{equation} i\partial_{t}\psi=(-\Delta)^{s}\psi-f(\psi), \qquad (0.1)\end{equation} where $0<s<1$, $f(\psi)=|\psi|^{p}\psi$ with $\frac{4s}{N}<p<\frac{4s}{N-2s}$ or $f(\psi)=(|x|^{-\gamma}\ast|\psi|^2)\psi$ with $2s<\gamma<\min\{N,4s\}$. To this end, we look for normalized solutions of the associated stationary equation \begin{equation} (-\Delta)^s u+\omega u-f(u)=0. \qquad (0.2) \end{equation} Firstly, by constructing a suitable submanifold of a $L^2$-sphere, we prove the existence of a normalized solution for (0.2) with least energy in the $L^2$-sphere, which corresponds to a normalized ground state standing wave of(0.1). Then, we show that each normalized ground state of (0.2) coincides a ground state of (0.2) in the usual sense. Finally, we obtain the sharp threshold of global existence and blow-up for (0.1). Moreover, we can use this sharp threshold to show that all normalized ground state standing waves are strongly unstable by blow-up.

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

0 major / 3 minor

Summary. The manuscript proves existence of normalized ground states (least-energy solutions on the L²-sphere) for the fractional NLS equation (0.1) with power nonlinearity in the range 4s/N < p < 4s/(N-2s) and with Hartree nonlinearity in 2s < γ < min{N,4s}. It constructs a suitable submanifold of the L²-sphere on which the energy is minimized, shows that these normalized solutions coincide with the usual (unconstrained) ground states of (0.2), derives the sharp energy threshold separating global existence from blow-up for the time-dependent problem, and uses the threshold to establish strong instability by blow-up of all such normalized standing waves.

Significance. If the proofs close, the work supplies a self-contained variational treatment of normalized solutions and their dynamical consequences in the fractional setting, covering both local and nonlocal nonlinearities. The constrained-minimization approach on a carefully chosen submanifold, together with the identification of normalized and unconstrained ground states and the resulting sharp threshold, is a standard but cleanly executed technique that yields falsifiable predictions on the blow-up/global-existence dichotomy.

minor comments (3)
  1. [Abstract] Abstract: the phrase 'each normalized ground state of (0.2) coincides a ground state' is missing the preposition 'with'.
  2. [Abstract] Abstract: 'of(0.1)' lacks a space before the parenthesis.
  3. [Introduction] The notation for the fractional Laplacian and the precise functional setting (e.g., the space H^s) should be recalled explicitly in the introduction before the variational arguments begin.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for the positive summary, significance assessment, and recommendation of minor revision. The report contains no listed major comments, so we have no specific points requiring response or rebuttal.

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The derivation proceeds by direct constrained minimization of the energy on a suitably chosen submanifold of the L2-sphere (within the stated subcritical parameter ranges that guarantee compactness), followed by comparison of the resulting critical point with the unconstrained ground state and extraction of a sharp energy threshold for the time-dependent problem. These steps rely on standard variational arguments and Sobolev embeddings rather than any self-referential definition, fitted parameter renamed as prediction, or load-bearing self-citation chain. No equation or claim reduces to its own input by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The paper rests on standard functional-analytic properties of the fractional Laplacian and Sobolev embeddings valid in the stated parameter ranges; no free parameters, new entities, or ad-hoc axioms are introduced beyond the usual domain assumptions for the equation.

axioms (2)
  • standard math The fractional Laplacian (-Δ)^s generates a well-defined quadratic form on the fractional Sobolev space H^s for 0 < s < 1.
    Invoked implicitly when writing the stationary equation (0.2) and the energy functional.
  • domain assumption The nonlinearity satisfies the given range conditions ensuring the embedding H^s → L^{p+2} is compact on bounded domains or under suitable decay.
    Required for the Palais-Smale condition and attainment of the infimum on the constrained manifold.

pith-pipeline@v0.9.0 · 5818 in / 1420 out tokens · 24557 ms · 2026-05-25T01:23:27.151870+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

52 extracted references · 52 canonical work pages · 1 internal anchor

  1. [1]

    Bartsch, L

    T. Bartsch, L. Jeanjean, Normalized solutions for nonlinear Sch r¨ odinger systems, Proc. Roy. Soc. Edinburgh Sect. A, 148 (2018) 225-242

  2. [2]

    Bartsch, L

    T. Bartsch, L. Jeanjean, N. Soave, Normalized solutions for a s ystem of coupled cubic Schr¨ odinger equations on R3, J. Math. Pures Appl., 106 (2016) 583-614

  3. [3]

    Bartsch, N

    T. Bartsch, N. Soave, A natural constraint approach to norm alized solutions of nonlinear Schr¨ odinger equations and systems, J. Funct. Anal., 272 (2017) 4998-5037. 23

  4. [4]

    Bartsch, N

    T. Bartsch, N. Soave, Multiple normalized solutions for a competin g system of Schr¨ odinger equations, Calc. Var. Partial Differential Equations, 58 (2019) 24 pp

  5. [5]

    Bellazzini, L

    J. Bellazzini, L. Jeanjean, On dipolar quantum gases in the unstab le regime, SIAM J. Math. Anal., 48 (2016) 2028-2058

  6. [6]

    Bellazzini, L

    J. Bellazzini, L. Jeanjean, T. Luo, Existence and instability of sta nding waves with prescribed norm for a class of Schr¨ odinger-Poisson equations, Proc. Lond. Math . Soc., 107 (2013) 303-339

  7. [7]

    Berestycki, T

    H. Berestycki, T. Cazenave, Instabilit´ e des ´ etats stationaires dans les ´ euations de Schr¨ oinger et de Klein-Gordon non lin´ eires, C. R. Acad. Sci. Paris S´ er. I Math., 293 ( 1981) 489-492

  8. [8]

    Bhattarai, On fractional Schr¨ odinger systems of Choquar d type, J

    S. Bhattarai, On fractional Schr¨ odinger systems of Choquar d type, J. Differential Equations, 263 (2017) 3197-3229

  9. [9]

    Br´ ezis, E

    H. Br´ ezis, E. H. Lieb, A relation between pointwise convergence of functions and convergence of functionals, Proc. Amer. Math. Soc., 88 (1983) 486-490

  10. [10]

    Normalized solutions to the mixed dispersion nonlinear Schr\"odinger equation in the mass critical and supercritical regime

    D. Bonheure, J.-B. Casteras, T. Gou, L. Jeanjean: Normalize d solutions to the mixed dispersion nonlinear Schr¨ odinger equation in the mass critical and supercritic al regime, arXiv:1802.09217, accepted in Trans. Amer. Math. Soc

  11. [11]

    Boulenger, D

    T. Boulenger, D. Himmelsbach, E. Lenzmann, Blowup for fractio nal NLS, J. Funct. Anal., 271 (2016) 2569-2603

  12. [12]

    Chang, Methods in Nonlinear Analysis, Springer-Verlag, 20 05

    K.-C. Chang, Methods in Nonlinear Analysis, Springer-Verlag, 20 05

  13. [13]

    Cazenave, Semilinear Schr¨ odinger equations, Courant Lecture Notes in Mathematics vol

    T. Cazenave, Semilinear Schr¨ odinger equations, Courant Lecture Notes in Mathematics vol. 10, New York University, Courant Institute of Mathematical Sciences, Ne w York; American Mathematical Society, Providence, RI, 2003

  14. [14]

    Cazenave, P.L

    T. Cazenave, P.L. Lions, Orbital stability of standing waves for some nonlinear Schr¨ odinger equa- tions, Comm. Math. Phys., 85 (1982) 549-561

  15. [15]

    Y. Cho, H. Hajaiej, G. Hwang, T. Ozawa, On the orbital stability of fractional Schr¨ odinger equations, Comm. Pure Appl. Anal., 13 (2014) 1267-1282

  16. [16]

    Y. Cho, G. Hwang, S. Kwon, S. Lee, On finite time blow-up for the mass-critical Hartree equations, Proc. Roy. Soc. Edinburgh Sect. A, 145 (2015) 467-479

  17. [17]

    Dinh, Well-posedness of nonlinear fractional Schr¨ odinger and wave equations in Sobolev spaces, Int

    V.D. Dinh, Well-posedness of nonlinear fractional Schr¨ odinger and wave equations in Sobolev spaces, Int. J. Appl. Math., 31 (2018) 483-525

  18. [18]

    Dinh, On instability of standing waves for the mass-supercr itical fractional nonlinear Schr¨ odinger equation, Z

    V.D. Dinh, On instability of standing waves for the mass-supercr itical fractional nonlinear Schr¨ odinger equation, Z. Angew. Math. Phys., 70 (2019) 17 pp

  19. [19]

    V.D. Dinh, B. Feng, On fractional nonlinear Schr¨ odinger equat ion with combined power-type non- linearities, Discrete Contin. Dyn. Syst., 39 (2019) 4565-4612

  20. [20]

    Feng, Ground states for the fractional Schr¨ odinger equ ation, Electron

    B. Feng, Ground states for the fractional Schr¨ odinger equ ation, Electron. J. Differential Equations, 127 (2013) 1-11

  21. [21]

    Feng, On the blow-up solutions for the fractional nonlinear S chr¨ odinger equation with combined power-type nonlinearities, Comm

    B. Feng, On the blow-up solutions for the fractional nonlinear S chr¨ odinger equation with combined power-type nonlinearities, Comm. Pure Appl. Anal., 17 (2018) 1785- 1804

  22. [22]

    B. Feng, R. Chen, J. Ren, Existence of stable standing waves f or the fractional Schr¨ odinger equations with combined power-type and Choquard-type nonlinearities, J. Ma th. Phys., 60 (2019) 051512 12 pp

  23. [23]

    B. Feng, H. Zhang, Stability of standing waves for the fraction al Schr¨ odinger-Choquard equation, Comput. Math. Appl., 75 (2018) 2499-2507. 24

  24. [24]

    B. Feng, H. Zhang, Stability of standing waves for the fraction al Schr¨ odinger-Hartree equation, J. Math. Anal. Appl., 460 (2018) 352-364

  25. [25]

    Frank, E

    R.L. Frank, E. Lenzmann, Uniqueness of nonlinear gound state s for fractional Laplacians in R, Acta Math., 210 (2013) 261-318

  26. [26]

    Frank, E

    R.L. Frank, E. Lenzmann, L. Silvestre, Uniqueness of radial so lutions for the fractional Laplacian, Comm. Pure Appl. Math., 69 (2016) 1671-1725

  27. [27]

    Fr¨ ohlich, G

    J. Fr¨ ohlich, G. Jonsson, E. Lenzmann, Boson stars as solitar y waves, Comm. Math. Phys., 274 (2007) 1-30

  28. [28]

    T. Gou, Z. Zhang, Normalized solutions to the Chern-Simons-Sc hr¨ odinger system, arXiv:1903.07306

  29. [29]

    T. Gou, L. Jeanjean, Multiple positive normalized solutions for no nlinear Schr¨ odinger systems, Nonlinearity, 31 (2018) 2319-2345

  30. [30]

    B. Guo, D. Huang, Existence and stability of standing waves for nonlinear fractional Schr¨ odinger equations, J. Math. Phys., 53 (2012) 083702

  31. [31]

    Guo, S.H

    Q. Guo, S.H. Zhu, Sharp threshold of blow-up and scattering fo r the fractional Hartree equation, J. Differential Equations, 264 (2018) 2802-2832

  32. [32]

    Jeanjean, Existence of solutions with prescribed norm for s emilinear elliptic equations, Nonlinear Anal

    L. Jeanjean, Existence of solutions with prescribed norm for s emilinear elliptic equations, Nonlinear Anal. 28 (1997) 1633-1659

  33. [33]

    Jeanjean, T

    L. Jeanjean, T. Luo, Z. Wang, Multiple normalized solutions for q uasi-linear Schr¨ odinger equations, J. Differential Equations, 259 (2015) 3894-3928

  34. [34]

    Y. Hong, Y. Sire, On fractional Schr¨ odinger equations in Sobo lev spaces, Comm. Pure Appl. Anal., 14 (2015) 2265-2282

  35. [35]

    Kirkpatrick, E

    K. Kirkpatrick, E. Lenzmann, G. Staffilani, On the continuum limit f or discrete NLS with long-range lattice interactions, Comm. Math. Phys., 317 (2013) 563-591

  36. [36]

    N, Laskin, Fractional Quantum Mechanics and L` evy Path Inte grals, Phys. Lett. A, 268 (2000) 298-304

  37. [37]

    N, Laskin, Fractional Schr¨ odinger equations, Physics Review E, 66 (2002) 056108

  38. [38]

    G. Li, X. Luo, Normalized solutions for the Chern-Simons-Schr¨ odinger equation in R2, Ann. Acad. Sci. Fenn. Math., 42 (2017) 405-428

  39. [39]

    Luo, Normalized standing waves for the Hartree equations, Journal of Differential Equations, 2019

    X. Luo, Normalized standing waves for the Hartree equations, Journal of Differential Equations, 2019

  40. [40]

    Moroz, J

    V. Moroz, J. Van Schaftingen, Groundstates of nonlinear Cho quard equations: existence, qualitative properties and decay asymptotics, J. Funct. Anal., 265 (2013) 15 3-184

  41. [41]

    C. Peng, Q. Shi, Stability of standing wave for the fractional no nlinear Schr¨ odinger equation, J. Math. Phys., 59 (2018) 011508, 11 pp

  42. [42]

    Saanouni, Strong instability of standing waves for the fract ional Choquard equation, J

    T. Saanouni, Strong instability of standing waves for the fract ional Choquard equation, J. Math. Phys., 59 (2018) 081509, 14 pp

  43. [43]

    Soave, Normalized ground states for the NLS equation with c ombined nonlinearities, arXiv:1811.00826

    N. Soave, Normalized ground states for the NLS equation with c ombined nonlinearities, arXiv:1811.00826

  44. [44]

    Soave, Normalized ground states for the NLS equation with c ombined nonlinearities: the Sobolev critical case, arXiv:1901.02003

    N. Soave, Normalized ground states for the NLS equation with c ombined nonlinearities: the Sobolev critical case, arXiv:1901.02003

  45. [45]

    M. I. Weinstein, Modulational stability of ground states of nonlin ear Schr¨ odinger equations, SIAM J. Math. Anal., 16 (1985) 472-491. 25

  46. [46]

    M. I. Weinstein, Lyapunov stability of ground states of nonlinea r dispersive evolution equations, Comm. Pure Appl. Math., 39 (1986) 51-67

  47. [47]

    Weinstein, Nonlinear Schr¨ odinger equations and sharp inte rpolation estimates, Comm

    M.I. Weinstein, Nonlinear Schr¨ odinger equations and sharp inte rpolation estimates, Comm. Math. Phys., 87 (1983) 567-576

  48. [48]

    Wu, Existence and stability of standing waves for nonlinear fr actional Schr¨ odinger equation with Hartree type nonlinearity, J

    D. Wu, Existence and stability of standing waves for nonlinear fr actional Schr¨ odinger equation with Hartree type nonlinearity, J. Math. Anal. Appl., 411 (2014) 530-54 2

  49. [49]

    Zhang, Stability of standing waves for nonlinear Schr¨ odinger equations with unbounded potentials, Z

    J. Zhang, Stability of standing waves for nonlinear Schr¨ odinger equations with unbounded potentials, Z. Angew. Math. Phys., 51 (2000) 498-503

  50. [50]

    Zhang, S.H

    J. Zhang, S.H. Zhu, Stability of standing waves for the nonlinear fractional Schr¨ odinger equation, J. Dynam. Differential Equations, 29 (2017) 1017-1030

  51. [51]

    Zhu, On the blow-up solutions for the nonlinear fractional S chr¨ odinger equation, J

    S.H. Zhu, On the blow-up solutions for the nonlinear fractional S chr¨ odinger equation, J. Differential Equations, 261 (2016) 1506-1531

  52. [52]

    Zhu, Existence of stable standing waves for the fractiona l Schr¨ odinger equations with combined nonlinearities, J

    S.H. Zhu, Existence of stable standing waves for the fractiona l Schr¨ odinger equations with combined nonlinearities, J. Evol. Equ., 17 (2017) 1003-1021. 26