NLS equation with competing inhomogeneous nonlinearities: ground states, blow-up, and scattering
Pith reviewed 2026-05-24 05:50 UTC · model grok-4.3
The pith
Solutions to the NLS with competing inhomogeneous nonlinearities scatter or blow up below the ground state energy threshold.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The equation admits ground states that are unique up to symmetry, nondegenerate, and unstable; below their energy level, the solution scatters to a free wave or blows up in finite time, with the proof relying on a scattering criterion and virial-type inequalities, and an upper bound on the blow-up rate is derived.
What carries the argument
The ground state energy threshold, defined variationally from the elliptic problem with the two competing power nonlinearities weighted by singular potentials.
If this is right
- Ground states exist, are symmetric, decay at infinity, and are unstable.
- Solutions with energy below the threshold either scatter or blow up.
- The blow-up rate is bounded from above when blow-up occurs.
- The dichotomy holds without scaling or translation invariance.
Where Pith is reading between the lines
- The approach could apply to other non-scale-invariant equations with position-dependent nonlinearities.
- Simulations might reveal how the competition between terms affects the blow-up dynamics.
- Extensions to higher dimensions or radial cases may follow similar lines.
Load-bearing premise
The parameters place the equation in the inter-critical regime where the competing terms yield a positive ground state energy that controls the long-time behavior.
What would settle it
A global solution with energy below the ground state energy that does not scatter would contradict the claimed dichotomy.
read the original abstract
We investigate a class of nonlinear equations of Schr\"odinger type with competing inhomogeneous nonlinearities in the non-radial inter-critical regime, \begin{align*} i \partial_t u +\Delta u &=|x|^{-b_1} |u|^{p_1-2} u - |x|^{-b_2} |u|^{p_2-2}u \quad \mbox{in} \,\, \mathbb{R} \times \mathbb{R}^N, \end{align*} where $N \geq 1$, $b_1, b_2>0$ and $p_1,p_2>2$. First, we establish the existence/nonexistence, symmetry, decay, uniqueness, non-degeneracy and instability of ground states. Then, we prove the scattering versus blowup below the ground state energy threshold. Our approach relies on Tao's scattering criterion and Dodson-Murphy's Virial/Morawetz inequalities. We also obtain an upper bound of the blow-up rate. The novelty here is that the equation does not enjoy any scaling invariance due to the presence of competing nonlinearities and the singular weights prevent the invariance by translation in the space variable. To the best of authors knowledge, this is the first time when inhomegeneous NLS equation with a focusing leading order nonlinearity and a defocusing perturbation is investigated.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript studies the NLS equation with competing inhomogeneous nonlinearities i∂_t u + Δu = |x|^{-b_1}|u|^{p_1-2}u - |x|^{-b_2}|u|^{p_2-2}u in the non-radial inter-critical regime (N ≥ 1, b_1, b_2 > 0, p_1, p_2 > 2). It first constructs and characterizes ground states (existence/nonexistence, symmetry, decay, uniqueness, non-degeneracy, instability). It then establishes a scattering-versus-blowup dichotomy below the ground-state energy threshold via Tao's scattering criterion and Dodson-Murphy virial/Morawetz inequalities, together with an upper bound on the blow-up rate. The setting lacks both scaling and translation invariance.
Significance. If the claims hold, the work supplies the first treatment of an inhomogeneous NLS with a focusing leading term and defocusing perturbation, extending the theory to a regime without scaling or translation invariance. The adaptation of Tao's criterion and Dodson-Murphy estimates to this competing-inhomogeneous setting, together with the ground-state analysis, constitutes a concrete advance.
minor comments (2)
- [Introduction] The precise parameter restrictions defining the non-radial inter-critical regime are described as implicit in the setup; an explicit list of the admissible ranges for p_1, p_2, b_1, b_2 and N should appear in the introduction or §2.
- Notation for the ground-state energy threshold E_* (or equivalent) is used before it is defined; introducing it immediately after the ground-state existence result would improve readability.
Simulated Author's Rebuttal
We thank the referee for the positive assessment of our manuscript, the recognition of its novelty in addressing the inhomogeneous NLS with competing nonlinearities in the absence of scaling and translation invariance, and the recommendation for minor revision. We appreciate the summary of our results on ground states and the scattering/blow-up dichotomy.
Circularity Check
No significant circularity in derivation chain
full rationale
The paper constructs ground-state existence, symmetry, uniqueness and instability results for the given inhomogeneous NLS, then applies Tao's scattering criterion together with Dodson-Murphy virial/Morawetz estimates to obtain the scattering-versus-blow-up dichotomy below the energy threshold. All cited tools are external (Tao, Dodson-Murphy) and the equation lacks scaling invariance by construction of the competing terms; no step reduces by definition to a fitted parameter, self-citation load-bearing premise, or ansatz imported from the authors' prior work. The derivation is therefore self-contained against standard functional-analytic machinery.
Axiom & Free-Parameter Ledger
axioms (2)
- domain assumption Standard Sobolev and Strichartz estimates hold for the inhomogeneous weights |x|^{-b_i}
- domain assumption The ground state energy threshold is well-defined and positive under the stated parameter conditions
Reference graph
Works this paper leans on
-
[1]
L. Aloui and S. Tayachi, Local well-posedness for the inhomogeneous nonlinear Schr ¨ odinger equation, Discrete Cont. Dyn. Syst., 41 (2021) 5409–5437
work page 2021
-
[2]
A. H. Ardila and M. Cardoso, Blow-up solutions and strong instability of ground states f or the inhomogeneous nonlinear Schr¨ odinger equation, Commun. Pure Appl. Anal., 20 (2021) 101–119
work page 2021
-
[3]
A. K. Arora, B. Dodson and J. Murphy, Scattering below the ground state for the 2d radial nonlinea r Schr¨ odinger equation, Proc. Amer. Math. Soc., 148 (2020), 1653–1663
work page 2020
-
[4]
T. Bartsch, T. Weth and M. Willem, Partial symmetry of least energy nodal solutions to some var iational problems, J. Anal. Math., 96 (2005), 1–18
work page 2005
-
[5]
J. Bellazzini, L. Forcella and V. Georgiev Ground state energy threshold and blow-up for NLS with compe ting nonlinearities, Ann. Sc. Norm. Super. Pisa Cl. Sci. (5), 24 (2023), 955–988
work page 2023
-
[6]
J. Bellazzini, V. D. Dinh and L. Forcella, Scattering for non-radial 3D NLS with combined nonlinearit ies, arXiv:2209.01600
-
[7]
J. Belmonte-Beitia, V. M. P´ erez-Garc ´ ıa, V. Vekslerchik and P. J. Torres, Lie symmetries and solitons in nonlinear systems with spatially inhomogeneous nonlinearities , Phys. Rev. Lett., 98 (2007), 064102
work page 2007
-
[8]
J. E. Brothers and W. P. Ziemer, Minimal rearrangements of Sobolev functions , J. Reine Angew. Math., 384 (1988), 153–179
work page 1988
-
[9]
L. Campos, Scattering of radial solutions to the inhomogeneous nonlin ear Schr¨ odinger equation, Nonlinear Anal., 202 (2021), Paper No. 112118, 17 pp
work page 2021
-
[10]
L. Campos and M. Cardoso, A virial-Morawetz approach to scattering for the non-radia l inhomogeneous NLS , Proc. Amer. Math. Soc., 150 (2022) 2007–2021
work page 2022
-
[11]
M. Cardoso, L. G. Farah, C. M. Guzm´ an and J. Murphy, Scattering below the ground state for the intercritical non-radial inhomogeneous NLS , Nonlinear Anal. Real World Appl., 68 (2022), Paper No. 103687, 19 pp
work page 2022
-
[12]
Cazenave, Semilinear Schr¨ odinger Equations, Courant Lecture Notes in Mathematics, AMS, 2003
T. Cazenave, Semilinear Schr¨ odinger Equations, Courant Lecture Notes in Mathematics, AMS, 2003. 46 T. GOU, M. MAJDOUB & T. SAANOUNI
work page 2003
-
[13]
Chen, On a class of nonlinear inhomogeneous Schr¨ odinger equatio n, J
J. Chen, On a class of nonlinear inhomogeneous Schr¨ odinger equatio n, J. Appl. Math. Comput., 32 (2010), 237–253
work page 2010
-
[14]
J. Chen and B. Guo, Sharp global existence and blowing up results for inhomogen eous Schr¨ odinger equations, Discrete Contin. Dyn. Syst. Ser. B, 8 (2007), 357–367
work page 2007
- [15]
- [16]
-
[17]
Y. Cho, S. Hong and K. Lee, On the global well-posedness of focusing energy-critical i nhomogeneous NLS , J. Evol. Equ., 20 (2020) 1349–1380
work page 2020
- [18]
-
[19]
C.V. Coffman, Uniqueness of the ground state solution for ∆u − u + u3 = 0 and a variational characterization of other solutions , Arch. Rational Mech. Anal., 46 (1972), 81–95
work page 1972
-
[20]
V. Combet and F. Genoud, Classification of minimal mass blow-up solutions for an L2 critical inhomogeneous NLS, J. Evol. Equ., 16 (2016), 483–500
work page 2016
-
[21]
E. Dancer and S. Santra, Singular perturbed problems in the zero mass case: asymptot ic behavior of spikes , Ann. Mat. Pura Appl., 189 (2010), 185–225
work page 2010
- [22]
-
[23]
V.D. Dinh, Blowup of H 1 solutions for a class of the focusing inhomogeneous nonline ar Schr¨ odinger equation, Nonlinear Anal., 174 (2018), 169–188
work page 2018
-
[24]
V.D. Dinh and S. Keraani, Long time dynamics of non-radial solutions to inhomogeneou s nonlinear Schr¨ odinger equations, SIAM J. Math. Anal., 54 (2021), 4765–4811
work page 2021
-
[25]
V. D. Dinh, M. Majdoub and T. Saanouni, Long time dynamics and blow-up for the focusing inhomogeneo us nonlinear Schr¨ odinger equation with spatially growing nonlinearity, J. Math. Phys., 64 (2023), Paper No. 081509, 41 pp
work page 2023
-
[26]
B. Dodson and J. Murphy, A new proof of scattering below the ground state for the 3D rad ial focusing cubic NLS , Proc. Amer. Math. Soc., 145 (2017), 4859–4867
work page 2017
-
[27]
B. Dodson and J. Murphy, A new proof of scattering below the ground state for the non-r adial focusing NLS , Math. Res. Lett., 25 (2018), 1805–1825
work page 2018
-
[28]
T. Duyckaerts, J. Holmer and S. Roudenko, Scattering for the non-radial 3D cubic nonlinear Schr¨ odin ger equa- tion, Math. Res. Lett., 15 (2008), 1233–1250
work page 2008
-
[29]
D. Fang, J. Xie and T. Cazenave, Scattering for the focusing energy-subcritical nonlinear Schr¨ odinger equation, Sci. China Math., 54 (2011), 2037–2062
work page 2011
-
[30]
L. G. Farah, Global well-posedness and blow-up on the energy space for th e inhomogeneous nonlinear Schr¨ odinger equation J. Evol. Equ., 16 (2016), 193–208
work page 2016
-
[31]
L. G. Farah and C. M. Guzm´ an, Scattering for the radial 3D cubic focusing inhomogeneous n onlinear Schr¨ odinger equation, J. Differential Equations, 262 (2017), 4175–4231
work page 2017
-
[32]
G. Fibich and X.-P. Wang, Stability of solitary waves for nonlinear Schr¨ odinger equ ations with inhomogeneous nonlinearities, Phys. D , 175 (2003), 96–108
work page 2003
-
[33]
Foschi, Inhomogeneous Strichartz estimates , J
D. Foschi, Inhomogeneous Strichartz estimates , J. Hyperbolic Differ. Equ., 2 (2005), 1–24
work page 2005
-
[34]
Genoud, A uniqueness result for ∆u − λu + V (|x|)up = 0 on R2, Adv
F. Genoud, A uniqueness result for ∆u − λu + V (|x|)up = 0 on R2, Adv. Nonlinear Stud., 11 (2011), 483–491
work page 2011
-
[35]
Genoud, An inhomogeneous, L2-critical, nonlinear Schr¨ odinger equation, Z
F. Genoud, An inhomogeneous, L2-critical, nonlinear Schr¨ odinger equation, Z. Anal. Anwend., 31 (2012), 283– 290
work page 2012
-
[36]
F. Genoud and C. A. Stuart, Schr¨ odinger equations with a spatially decaying nonlinearity, existence and stability of standing waves , Discrete Contin. Dyn. Syst., 21 (2008), 137–186
work page 2008
-
[37]
N. Ghoussoub, Duality and Perturbation Methods in Critical Point Theory , Cambridge Tracts in Mathematics, vol. 107, Cambridge University Press, Cambridge, 1993
work page 1993
-
[38]
Gill, Optical guiding of laser beam in nonuniform plasma , Pramana, 55 (2000), 835–842
T.S. Gill, Optical guiding of laser beam in nonuniform plasma , Pramana, 55 (2000), 835–842. COMPETING INLS 47
work page 2000
-
[39]
J. Ginibre, G. Velo, On a class of nonlinear Schr¨ odinger equations. I. The Cauch y problem, general case , J. Functional Analysis, 32 (1979), 1–32
work page 1979
-
[40]
R.T. Glassey, On the blowing up of solutions to the Cauchy problem for nonli near Schr¨ odinger equations, J. Math. Phys., 18 (1977), 1794–1797
work page 1977
-
[41]
Guzm´ an, On well posedness for the inhomogeneous nonlinear Schr¨ odi nger equation , Nonlinear Anal
C.M. Guzm´ an, On well posedness for the inhomogeneous nonlinear Schr¨ odi nger equation , Nonlinear Anal. Real World Appl., 37 (2017), 249–286
work page 2017
-
[42]
C.M. Guzm´ an and J. Murphy, Scattering for the non-radial energy-critical inhomogene ous NLS , J. Differential Equations, 295 (2021), 187–210
work page 2021
-
[43]
H. Hajaiej and C. A. Stuart, On the variational approach to the stability of standing wav es for the nonlinear Schr¨ odinger equation, Adv. Nonlinear Stud., 4 (2004), 469–501
work page 2004
-
[44]
J. Holmer and S. Roudenko, A sharp condition for scattering of the radial 3D cubic nonli near Schr¨ odinger equations, Commun Math Phys., 282 (2008), 435–467
work page 2008
-
[45]
Kato, Growth properties of solutions of the reduced wave equation with a variable coefficient , Comm
T. Kato, Growth properties of solutions of the reduced wave equation with a variable coefficient , Comm. Pure Appl. Math., 12 (1959), 403–425
work page 1959
-
[46]
M. Keel and T. Tao, Endpoint Strichartz estimates , Amer. J. Math., 120 (1998), 955–980
work page 1998
-
[47]
C. E. Kenig and F. Merle, Global well-posedness, scattering and blow up for the energ ycritical, focusing, nonlinear Schr¨ odinger equation in the radial case, Invent. Math., 166 (2006), 645–675
work page 2006
- [48]
- [49]
-
[50]
R. Killip and M. Visan, The focusing energy-critical nonlinear Schr¨ odinger equa tion in dimensions five and higher, Amer. J. Math., 132 (2010) , 361–424
work page 2010
-
[51]
Y.S. Kivshar and G. P. Agrawal, Optical Solitons: From Fibers to Photonic Crystals , Academic Press 2003
work page 2003
-
[52]
M. K. Kwong, Uniqueness of positive solutions of ∆u − u + up = 0 in Rn, Arch. Rational Mech. Anal., 105 (1989), 243–266
work page 1989
-
[53]
E.H. Lieb and M. Loss, Analysis, Graduate Studies in Mathematics, AMS, Providence, Rhode I sland, 2001
work page 2001
-
[54]
Lions, The concentration-compactness principle in the calculus o f variations
P-L. Lions, The concentration-compactness principle in the calculus o f variations. The locally compact case, part II, Ann. Inst. Henri Poincar´ e, Anal. Non Lin´ eaire,1 (1984), 223–283
work page 1984
- [55]
- [56]
-
[57]
F. Merle, Determination of blow-up solutions with minimal mass for no nlinear Schr¨ odinger equations with critical power, Duke Math. J., 69 (1993), 427–454
work page 1993
-
[58]
Merle, Nonexistence of minimal blow-up solutions of equations iut = − ∆u − k(x)|u|4/Nu in RN , Ann
F. Merle, Nonexistence of minimal blow-up solutions of equations iut = − ∆u − k(x)|u|4/Nu in RN , Ann. Inst. H. Poincar´ e Phys. Th´ eor.,64 (1996), 33–85
work page 1996
-
[59]
F. Merle and P. Rapha¨ el, On universality of blow-up profile for the L2-critical nonlinear Schr¨ odinger equation, Invent. Math., 156 (2004), 565–672
work page 2004
-
[60]
F. Merle and P. Rapha¨ el,Blow-up dynamic and upper bound on the blow-up rate for criti cal nonlinear Schr¨ odinger equation, Ann. of Math., 16 (2005), 157–222
work page 2005
-
[61]
F. Merle and P. Rapha¨ el, On a sharp lower bound on the blow-up rate for the L2-critical nonlinear Schr¨ odinger equation, J. Amer. Math. Soc., 19 (2006), 37–90
work page 2006
- [62]
-
[63]
F. Merle and Y. Tsutsumi, L2 concentration of blow up solutions for the nonlinear Schr¨ o dinger equation with critical power nonlinearity , J. Differential Equations, 84 (1990), 205–214
work page 1990
-
[64]
C. Miao, J. Murphy and J. Zheng, Scattering for the non-radial inhomogeneous NLS , Math. Res. Lett., 28 (2021), 1481–1504
work page 2021
-
[65]
C. Miao, G. Xu, and L. Zhao, The dynamics of the 3D radial NLS with the combined terms , Comm. Math. Phys., 318 (2013), 767–808. 48 T. GOU, M. MAJDOUB & T. SAANOUNI
work page 2013
-
[66]
C. Miao, T. Zhao and J. Zheng, On the 4D nonlinear Schr¨ odinger equation with combined terms under the energy threshold, Calc. Var. Partial Differential Equations, 56 (2017), Paper No. 179, 39 pp
work page 2017
-
[67]
T. Ogawa and Y. Tsutsumi, Blow-up of H 1 solutions for the one-dimensional nonlinear Schr¨ odinger equation with critical power nonlinearity , Proc. Am. Math. Soc., 111 (1991), 487–96
work page 1991
-
[68]
Y.G. Oh, On positive multi-lump bound states of nonlinear Schr¨ odin ger equations under multiple well potential , Comm. Math. Phys., 131 (1990), 223–253
work page 1990
-
[69]
P. Raphae ¨l and J. Szeftel, Existence and uniqueness of minimal blow-up solutions to an inhomogeneous mass critical NLS , J. Amer. Math. Soc., 24 (2011), 471–546
work page 2011
-
[70]
N. Shioji and K. Watanabe, A generalized Pohozaev identity and uniqueness of positive radial solutions of ∆u + g(r)u + h(r)up = 0, J. Differential Equations, 255 (2013), 4448–4475
work page 2013
-
[71]
N. Shioji and K. Watanabe, Uniqueness and nondegeneracy of positive radial solutions of div(ρ∇ u) + ρ(− gu + hup) = 0, Calc. Var. Partial Differential Equations, 55 (2016), Art. 32, 42 pp
work page 2016
-
[72]
A. Stefanov, On the normalized ground states of second order PDE’s with mi xed power non-linearities , Comm. Math. Phys., 369 (2019), 929–971
work page 2019
-
[73]
W. A. Strauss, Existence of solitary waves in higher dimensions , Comm. Math. Phys., 55 (1977), 149–162
work page 1977
-
[74]
Van Schaftingen, Explicit approximation of the symmetric rearrangement by p olarizations, Arch
J. Van Schaftingen, Explicit approximation of the symmetric rearrangement by p olarizations, Arch. Math., 93 (2009), 181–190
work page 2009
-
[75]
Yanagida, Uniqueness of positive radial solutions of ∆u + g(r)u + h(r)up = 0 in Rn, Arch
E. Yanagida, Uniqueness of positive radial solutions of ∆u + g(r)u + h(r)up = 0 in Rn, Arch. Rational Mech. Anal., 115 (1991), 257–274
work page 1991
-
[76]
E. Yanagida, Uniqueness of positive radial solutions of ∆u+f (u, |x|) = 0, Nonlinear Anal., 19 (1992), 1143–1154
work page 1992
-
[77]
C. Sulem and P.-L. Sulem, The Nonlinear Schr¨ odinger Equation: Self-Focusing and Wave Collapse , Appl. Math. Sci., 139, Springer-Verlag, New York, 1999
work page 1999
-
[78]
T. Tao, On the asymptotic behavior of large radial data for a focusin g non-linear Schr¨ odinger equation, Dyn. Partial. Differ. Equ., 1 (2004), 1–48
work page 2004
-
[79]
Tao, Nonlinear Dispersive Equations: Local and Global Analysis , CBMS Reg
T. Tao, Nonlinear Dispersive Equations: Local and Global Analysis , CBMS Reg. Conf. Ser. Math., 106, American Mathematical Society, Providence, RI, 2006
work page 2006
-
[80]
T. Tao, M. Visan and Y. Zhang, The nonlinear Schr¨ odinger equation with combined power-t ype nonlinearities , Comm. Partial Differential Equations, 32 (2007), 1281–1343
work page 2007
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.