REVIEW 2 major objections 3 minor 1 cited by
Interior and Boundary Regularity of Mixed Local Nonlocal Problem with Singular Data and Its Applications
T0 review · 2 major / 3 minor · reviewed 2026-08-12 · deepseek-v4-flash
Pith's one-line read Under the minimal condition $p>sq$, solutions to the singular mixed local-nonlocal equation are $C^{1,\alpha}$ up to the boundary when the singularity is mild, and $C^\alpha$ when it is strong.
desk verdict Boundary regularity for singular data in the hard range sq<p<q is new and worth engaging, but the main barrier argument silently requires q > 1/(1−s), so the stated range is not proved. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The argument is carried by barrier functions built from powers of the distance to the boundary, $d(x)^\alpha$, with the exponent constrained by the fractional $q$-Laplacian: $(-\Delta)_q^s d^\alpha$ stays bounded in $L^\infty$ near the boundary precisely when $\alpha>qs/(q-1)$. The barriers give upper bounds $u\le C d^\alpha$ and, together with Hopf's lemma for the regular mixed operator, lower bounds $u\ge C d$. Interior $C^{1,\theta}_{\rm loc}$ regularity is obtained from Caccioppoli estimates and De Giorgi iteration, and boundary gradient regularity by flattening the boundary and comparing $u$ with the solution of a constant-coefficient $p$-Laplacian Dirichlet problem on half-balls.
What would settle it
Take a half-ball and $u=d^\alpha$ with $\alpha=qs/(q-1)$; compute $(-\Delta)_q^s u$ near the flat boundary. If it is bounded instead of diverging like a negative power of $d$, the barrier threshold in Theorem 3.8 is not necessary. Alternatively, numerically solve (1.1) in a disk with mild singularity and check whether the normal derivative at the boundary is continuous; a failure would disprove $C^{1,\alpha}$ boundary regularity in that range.
Extended reading notes
Core claim
On the paper's own terms, the central discovery is that the singular mixed operator $-\Delta_p+(-\Delta)_q^s$ behaves like its regular counterpart at the boundary: a weak solution with data of order $d(x)^{-\gamma}$ still has a definite boundary trace of power type, and its gradient is Hölder continuous up to the boundary whenever the singularity is mild ($\gamma+\delta<1$). In the strongly singular case $\gamma+\delta>1$, the solution itself is Hölder continuous up to the boundary, though the gradient may blow up. The same framework yields a strong comparison principle for $C^{1,\alpha}$ solutions with singular term, and existence and uniqueness results for perturbed problems. The authors state these are the first boundary regularity results of this kind for singular data in the range $sq<p<q$, where the nonlocal part is not dominated by the local gradient term.
Load-bearing premise
The load-bearing premise is that the previously proved Hopf lemma and global gradient estimates for the same mixed operator without singularity remain valid for the singular weak solutions studied here; if that transfer fails, the boundary regularity argument collapses.
Editorial extensions
If this is right
- If the central claim is correct, singular weak solutions of (1.1) have a definite boundary profile: comparable to the distance function from below and bounded by a power of the distance from above, with the power depending only on $q,s$ and the singularity parameters.
- In the mildly singular range $\gamma+\delta<1$, the gradient is Hölder continuous up to the boundary, so boundary-value techniques such as Hopf-type arguments and Picone identities apply to the singular problem.
- The strong comparison principle implies uniqueness of the solution for sublinear perturbations and gives strict ordering of solutions, which is the tool needed for subcritical superlinear existence by truncation.
- Under the same regularity, the problem with $F(x,u)=u^l$ has a unique $C^{1,\alpha}$ solution for sublinear $l$, and a $C^{1,\alpha}$ solution for superlinear subcritical $l$ for small $\lambda$.
Reading between the lines
- The exponent threshold $\alpha>qs/(q-1)$ is probably not an artifact of the proof: it is the same threshold that makes the fractional $q$-Laplacian of the distance power locally bounded, so the boundary Hölder exponent may be optimal; a test would be explicit radial solutions for $p=q$ in a ball.
- The method likely extends to data with more general singular weights than $K_\gamma(x)u^{-\delta}$, as long as the barrier can dominate the weight; one can test by replacing $K_\gamma$ with a weight that oscillates between two distance powers.
- The strong comparison principle for the singular nonlinearity is a natural stepping stone to a Hopf-type lemma for the fractional part, which the authors note remains open for singular $(-\Delta)_p^s$.
- The regularity results should allow variational methods, such as Sobolev-versus-Hölder minimizer arguments, for mixed local-nonlocal singular functionals, by analogy with the local $p$-Laplacian theory.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper studies the mixed local-nonlocal quasilinear problem -Δ_p u + (-Δ)_q^s u = K_γ(x) u^{-δ} + F(x,u) with positive singular data and zero Dirichlet condition. It claims interior C^{1,θ}_{loc} regularity for locally bounded data, boundary C^{1,α} regularity when γ+δ<1, boundary C^α regularity when γ+δ>1, a strong comparison principle, and two applications (sublinear and subcritical perturbations). The proofs use Caccioppoli estimates, De Giorgi iteration, barrier functions, and a perturbative comparison with solutions of frozen-coefficient problems, following the strategy of De Filippis–Mingione and Antonini–Cozzi.
Significance. If the boundary regularity results hold in the advertised range sq<p<q, they would be a valuable step for singular mixed local-nonlocal problems, with consequences for comparison principles and existence theory. The paper develops useful technical machinery, including detailed interior estimates and a Campanato-style boundary gradient estimate. However, the central boundary barrier requires an additional condition on q,s that is not assumed, so the main advertised range is not established as stated. The strong comparison principle and local regularity parts appear more robust.
major comments (2)
- [§3.3.1, Theorem 3.8 and Eq. (3.20)] The proof constructs a barrier ω_ρ = (d_e)^α_+ and requires α ∈ (qs/(q−1), 1). Such an α exists only when qs/(q−1) < 1, i.e. q > 1/(1−s). The manuscript assumes only p > sq (Abstract and Section 1). For q=2, s=1/2 and p∈(1,2), one has p>sq but qs/(q−1)=1, so the admissible interval is empty. Thus even granting [35, Eqn (5.23)] and [2] in full, the two required inequalities α>qs/(q−1) and α<1 are incompatible. This is an internal gap, not merely a dependence on an unpublished preprint. Consequently Theorem 3.8(a), and with it Theorems 2.3 and 2.5 (and Theorem 2.10 via Theorem 2.5), are not proved under the stated minimal assumption p>sq. The statements must either add q>1/(1−s) or be supplied with a different boundary barrier.
- [§4.2, proof of Theorem 2.5, final paragraph] The lower bound C d(x) ≤ u is obtained by invoking Theorem 5.1, but Theorem 5.1 assumes γ ≤ min{1+s−1/q, 2−1/p}. This condition is not implied by the hypotheses of Theorem 2.5. For example, with s=0.2, q=2, δ=0.1 and γ=0.71, one has γ+δ=0.81<1 and γ+(1/q−s)(1−δ)=0.98<1, but 1+s−1/q=0.7<γ. The proof therefore needs either a comparison principle valid under the stated assumptions or an additional hypothesis guaranteeing the applicability of Theorem 5.1.
minor comments (3)
- [§3.3.1, Theorem 3.8 statement] The displayed condition 'for every µ ∈ ( qs/(q−1), 1, )' is malformed and should be corrected; the intended interval is (qs/(q−1), 1).
- [§4 and §7] Lemma 4.2, Theorem 4.1 and Lemma 7.3 are only sketched or deferred to 'standard' arguments. Since these results justify the approximation u_ε and the existence steps in the applications, the authors should either give complete proofs or cite precise published statements.
- [Throughout] There are numerous typographical issues (e.g. 'T o', 'for for', inconsistent use of N and n in the fractional exponent, and duplicated definitions of d_e). A careful proofreading is needed.
Circularity Check
No significant circularity: the central regularity theorems are proved by direct estimates, and the self-cited technical lemmas are independent computational tools whose hypotheses do not include the target conclusions.
full rationale
This paper does not exhibit circular reasoning. The central regularity claims (Theorems 2.2, 2.3, 2.5, and 2.6) are established through direct Caccioppoli estimates, De Giorgi-type iteration, explicit barrier constructions with powers of the distance function, and a perturbative comparison with frozen-coefficient p-harmonic problems. The only self-citations are technical lemmas imported from the authors' previous work: [35, Eqn (5.23)] and [37, Theorem 3.11] for the fractional q-Laplacian of d^alpha, and [34] for comparison arguments. These are parameter-free computations whose stated hypotheses (such as alpha > qs/(q-1)) do not include the boundary regularity conclusion; they are not fitted to the target solution and do not redefine the target. The main interior C^{1,theta} input is the external result [20, Theorem 6.1]. No fitted parameter is renamed as a prediction, no known pattern is presented under new coordinates, and no uniqueness theorem is imported from same-author work to force the choice of barrier exponents. A possible internal gap noted by a skeptical reader -- the barrier requires an alpha with qs/(q-1) < alpha < 1, which is empty when q <= 1/(1-s) -- would be a correctness failure in the proof as written, not a circularity, because the claimed conclusion is not assumed through those lemmas. Accordingly, the circularity score is 0.
Assumptions & free parameters
assumptions (7)
- domain assumption p > sq
- domain assumption Ω is a bounded open set with smooth boundary and Kγ is comparable to d^{-γ} in Ω
- domain assumption Hopf lemma and global gradient regularity for the mixed local-nonlocal operator hold for the class of solutions considered, as established in [2, Theorems 1.1 and 1.2]
- domain assumption The fractional q-Laplacian of the distance power d^α is bounded in L∞ near the boundary when α > qs/(q-1), from [35, Eqn (5.23)]
- domain assumption The interior C^{1,α} regularity theorem of De Filippis-Mingione [20, Theorem 6] applies to the local solutions of the mixed operator, quoted as Theorem 3.7
- domain assumption Weak solutions satisfy the integrability and positivity conditions of Definition 2.4 (u ∈ X(Ω) for local solutions, or u^θ ∈ W^{1,p}_0 ∩ W^{s,q}_0 for some θ ≥ 1 and ess inf_K u > 0 for every K compact)
- ad hoc to paper q > 1/(1-s) for Theorem 2.8
Cite this review
Pith. "Pith review of Interior and Boundary Regularity of Mixed Local Nonlocal Problem with Singular Data and Its Applications." pith.science (2026). https://pith.science/paper/4LLHLA7I
@misc{pith2026241118505,
author = {Pith},
title = {Pith review of: Interior and Boundary Regularity of Mixed Local Nonlocal Problem with Singular Data and Its Applications},
year = {2026},
howpublished = {\url{https://pith.science/paper/4LLHLA7I}},
note = {Machine review of arXiv:2411.18505}
}
abstract
In this article, we examine the H\"older regularity of solutions to equations involving a mixed local-nonlocal nonlinear nonhomogeneous operator $\fp + \fqs$ with singular data, under the minimal assumption that $p> sq$. The regularity result is twofold: we establish interior gradient H\"older regularity for locally bounded data and boundary regularity for singular data. We prove both boundary H\"older and boundary gradient H\"older regularity depending on the degree of singularity. Additionally, we establish a strong comparison principle for this class of problems, which holds independent significance. As the applications of these qualitative results, we further study sublinear and subcritical perturbations of singular nonlinearity.
Forward citations
Cited by 1 Pith paper
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Regularity results for a class of mixed local and nonlocal singular problems involving distance function
For mixed local-nonlocal singular quasilinear elliptic problems, the authors establish existence, uniqueness under a boundary-weight restriction, sharp Sobolev regularity, boundary behavior, and Hölder regularity with...
Reference graph
Works this paper leans on
-
[37]
Interior and boundary regularity results for strongly nonhomogeneous p, q-fractional problems
Jacques Giacomoni, Deepak Kumar , and Konijeti Sreenad h. Interior and boundary regularity results for strongly nonhomogeneous p, q-fractional problems. Adv. Calc. Var ., 16(2):467–501, 2023
work page 2023
-
[2]
Global gradient regularity and a Hopf lemma for quasilinear operators of mixed local-nonlocal type
Carlo Alberto Antonini and Matteo Cozzi. Global gradien t regularity and a hopf lemma for quasilinear operators of mixed local-nonlocal type. arXiv preprint arXiv:2308.06075 , 2023
work page Pith review arXiv 2023
-
[1]
Pos itive solutions to a fractional equation with singular non- linearity .J
Adimurthi, Jacques Giacomoni, and Sanjiban Santra. Pos itive solutions to a fractional equation with singular non- linearity .J. Differential Equations , 265(4):1191–1226, 2018
work page 2018
-
[3]
Multiplicity results for nonhomogeneous elliptic equations with singular nonlinearities
Rakesh Arora. Multiplicity results for nonhomogeneous elliptic equations with singular nonlinearities. Commun. Pure Appl. Anal. , 21(6):2253–2269, 2022
work page 2022
-
[4]
Regularity results for a class of nonlinear fractional laplacian and singular problems
Rakesh Arora, Jacques Giacomoni, and Guillaume Warnaul t. Regularity results for a class of nonlinear fractional laplacian and singular problems. Nonlinear Differential Equations and Applications NoDEA , 28:1–35, 2021
work page 2021
-
[5]
Rakesh Arora and Vicen¸ tiu D. R˘adulescu. Combined effects in mixed local–nonlocal statio nary problems. Proceed- ings of the Royal Society of Edinburgh Section A: Mathematic s, page 1–47, 2023
work page 2023
-
[6]
Kaushik Bal and Stuti Das. Multiplicity of solutions for mixed local-nonlocal elliptic equations with singular non - linearity .arXiv preprint, arXiv:2405.05832 , 2024
arXiv 2024
-
[7]
Kaushik Bal and Stuti Das. Regularity results for a class of mixed local and nonlocal singular problems involving distance function. arXiv preprint, arXiv:2411.14217 , 2024
work page Pith review arXiv 2024
Show all 52 references
-
[8]
Semilinear problems for the fractional laplacian with a singular nonlinearity
Begoña Barrios, Ida De Bonis, María Medina, and Ireneo Pe ral. Semilinear problems for the fractional laplacian with a singular nonlinearity . Open Math., 13(1):390–407, 2015
2015
-
[9]
Local and nonlocal anisotropic transport in reversed shear mag- netic fields: Shearless cantori and nondiffusive transport
Daniel Blazevski and Diego del Castillo-Negrete. Local and nonlocal anisotropic transport in reversed shear mag- netic fields: Shearless cantori and nondiffusive transport . Physical Review E—Statistical, Nonlinear , and Soft Matter Physics, 87(6):063106, 2013
2013
-
[10]
Generalized Picone i nequalities and their applications to ( p,q)-Laplace equa- tions
Vladimir Bobkov and Mieko Tanaka. Generalized Picone i nequalities and their applications to ( p,q)-Laplace equa- tions. Open Math., 18(1):1030–1044, 2020
2020
-
[11]
Semi-groupes de Feller sur une variété à bord compacte et problèmes aux limites intégro-différentiels du second o rdre donnant lieu au principe du maximum
Jean-Michel Bony , Philippe Courrège, and Pierre Priou ret. Semi-groupes de Feller sur une variété à bord compacte et problèmes aux limites intégro-différentiels du second o rdre donnant lieu au principe du maximum. Ann. Inst. Fourier (Grenoble), 18:369–521, 1968
1968
-
[12]
Hi gher Hölder regularity for the fractional p-Laplacian in the superquadratic case
Lorenzo Brasco, Erik Lindgren, and Armin Schikorra. Hi gher Hölder regularity for the fractional p-Laplacian in the superquadratic case. Adv. Math., 338:782–846, 2018. 38 R. DHANYA, JACQUES GIACOMONI, AND RIT ABRA T A JANA
2018
-
[13]
The second eigenvalue o f the fractional p-Laplacian
Lorenzo Brasco and Enea Parini. The second eigenvalue o f the fractional p-Laplacian. Adv. Calc. Var ., 9(4):323–355, 2016
2016
-
[14]
Hölder regula rity for weak solutions to nonlocal double phase prob- lems
Sun-Sig Byun, Jihoon Ok, and Kyeong Song. Hölder regula rity for weak solutions to nonlocal double phase prob- lems. J. Math. Pures Appl. (9) , 168:110–142, 2022
2022
-
[15]
Cancelier
C. Cancelier . Problèmes aux limites pseudo-différent iels donnant lieu au principe du maximum. Comm. Partial Differential Equations, 11(15):1677–1726, 1986
1986
-
[16]
Nonlocal problems with singular nonlinearity .Bull
Annamaria Canino, Luigi Montoro, Berardino Sciunzi, a nd Marco Squassina. Nonlocal problems with singular nonlinearity .Bull. Sci. Math. , 141(3):223–250, 2017
2017
-
[17]
Variational properties of nonlocal singular problems
Annamaria Canino, Luigi Montoro, Berardino Sciunzi, a nd Alessandro Trombetta. Variational properties of nonlocal singular problems. Nonlinearity, 36(8):4034–4052, 2023
2023
-
[18]
Existence and uniqueness for p-Laplace equa- tions involving singular nonlinearities
Annamaria Canino, Berardino Sciunzi, and Alessandro T rombetta. Existence and uniqueness for p-Laplace equa- tions involving singular nonlinearities. NoDEA Nonlinear Differential Equations Appl. , 23(2):Art. 8, 18, 2016
2016
-
[19]
M. G. Crandall, P. H. Rabinowitz, and L. Tartar . On a Diri chlet problem with a singular nonlinearity . Comm. Partial Differential Equations, 2(2):193–222, 1977
1977
-
[20]
Gradient regularity in mixed local and nonlocal problems
Cristiana De Filippis and Giuseppe Mingione. Gradient regularity in mixed local and nonlocal problems. Mathema- tische Annalen, pages 1–68, 2022
2022
-
[21]
Del Pezzo, Raúl Ferreira, and Julio D
Leandro M. Del Pezzo, Raúl Ferreira, and Julio D. Rossi. Eigenvalues for a combination between local and nonlocal p-Laplacians. Fract. Calc. Appl. Anal. , 22(5):1414–1436, 2019
2019
-
[22]
Dhanya and M
R. Dhanya and M. S. Indulekha. Parameter estimates and a uniqueness result for double phase problem with a singular nonlinearity .J. Math. Anal. Appl. , 530(1):Paper No. 127608, 11, 2024
2024
-
[23]
Dhanya, M
R. Dhanya, M. S. Indulekha, and Ritabrata Jana. Strong c omparison principle for a p-Laplace equation involving singularity and its applications. Appl. Math. Lett. , 135:Paper No. 108403, 8, 2023
2023
-
[24]
Hitchhiker’s guide to the fractional Sobolev space s
Eleonora Di Nezza, Giampiero Palatucci, and Enrico Val dinoci. Hitchhiker’s guide to the fractional Sobolev space s. Bull. Sci. Math. , 136(5):521–573, 2012
2012
-
[25]
(Non)local logistic equations with Neumann condi - tions
Serena Dipierro, Edoardo Proietti Lippi, and Enrico Va ldinoci. (Non)local logistic equations with Neumann condi - tions. Ann. Inst. H. Poincaré C Anal. Non Linéaire , 40(5):1093–1166, 2023
2023
-
[26]
Serena Dipierro and Enrico Valdinoci. Description of a n ecological niche for a mixed local/nonlocal dispersal: an evolution equation and a new neumann condition arising from the superposition of brownian and lévy processes. Physica A: Statistical Mechanics and its Application...
2021
-
[27]
Fractiona l p-eigenvalues
Giovanni Franzina and Giampiero Palatucci. Fractiona l p-eigenvalues. Riv. Math. Univ. Parma (N.S.), 5(2):373–386, 2014
2014
-
[28]
Fulks and J
W. Fulks and J. S. Maybee. A singular non-linear equatio n. Osaka Math. J. , 12:1–19, 1960
1960
-
[29]
On a class of mixed local and nonlocal semilinear elliptic equation with singular nonlinearity
Prashanta Garain. On a class of mixed local and nonlocal semilinear elliptic equation with singular nonlinearity . J. Geom. Anal., 33(7):Paper No. 212, 20, 2023
2023
-
[30]
On the regularity theory for mixed anisotropic and nonlocal p-Laplace equations and its applications to singular proble ms
Prashanta Garain, Wontae Kim, and Juha Kinnunen. On the regularity theory for mixed anisotropic and nonlocal p-Laplace equations and its applications to singular proble ms. Forum Math., 36(3):697–715, 2024
2024
-
[31]
Mixed local and nonlocal Sobolev inequalities with extremal and associ- ated quasilinear singular elliptic problems
Prashanta Garain and Alexander Ukhlov . Mixed local and nonlocal Sobolev inequalities with extremal and associ- ated quasilinear singular elliptic problems. Nonlinear Anal., 223:Paper No. 113022, 35, 2022
2022
-
[32]
Giacomoni and K
J. Giacomoni and K. Saoudi. W 1,p 0 versus C 1 local minimizers for a singular and critical functional. J. Math. Anal. Appl., 363(2):697–710, 2010
2010
-
[33]
Discrete Picone inequalities and applica- tions to non local and non homogenenous operators
Jacques Giacomoni, Abdelhamid Gouasmia, and Abdelhafi d Mokrane. Discrete Picone inequalities and applica- tions to non local and non homogenenous operators. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser . A Mat. RACSAM , 116(3):Paper No. 100, 21, 2022
2022
-
[34]
Sreenadh
Jacques Giacomoni, Deepak Kumar , and K. Sreenadh. Sobo lev and Hölder regularity results for some singular nonhomogeneous quasilinear problems. Calc. Var . Partial Differential Equations, 60(3):Paper No. 121, 33, 2021
2021
-
[35]
Sreenadh
Jacques Giacomoni, Deepak Kumar , and K. Sreenadh. Höld er regularity results for parabolic nonlocal double phase problems. Adv. Differential Equations , 29(11-12):899–950, 2024. REGULARITY OF MIXED LOCAL NONLOCAL PROBLEM WITH SINGULAR DA T A 39
2024
-
[36]
A qualitative study of (p, q) singular parabolic equa- tions: local existence, Sobolev regularity and asymptotic behavior .Adv
Jacques Giacomoni, Deepak Kumar , and Konijeti Sreenad h. A qualitative study of (p, q) singular parabolic equa- tions: local existence, Sobolev regularity and asymptotic behavior .Adv. Nonlinear Stud. , 21(1):199–227, 2021
2021
-
[38]
Existence of three positive solutions for a nonlocal singular Dirichlet boundary problem
Jacques Giacomoni, T uhina Mukherjee, and Konijeti Sre enadh. Existence of three positive solutions for a nonlocal singular Dirichlet boundary problem. Adv. Nonlinear Stud. , 19(2):333–352, 2019
2019
-
[39]
Sobolev versus hölder local minimizers and existence of m ul- tiple solutions for a singular quasilinear equation
Jacques Giacomoni, Ian Schindler , and Peter Taká ˇc. Sobolev versus hölder local minimizers and existence of m ul- tiple solutions for a singular quasilinear equation. Annali della Scuola normale superiore di Pisa-Classe di sci enze, 6(1):117–158, 2007
2007
-
[40]
Direct methods in the calculus of variations
Enrico Giusti. Direct methods in the calculus of variations . World Scientific, 2003
2003
-
[41]
Sreenadh
Divya Goel, Deepak Kumar , and K. Sreenadh. Regularity a nd multiplicity results for fractional (p, q)-Laplacian equations. Commun. Contemp. Math. , 22(8):1950065, 37, 2020
2020
-
[42]
Pa pageorgiou
Antonio Iannizzotto, Sunra Mosconi, and Nikolaos S. Pa pageorgiou. On the logistic equation for the fractional p-Laplacian. Math. Nachr ., 296(4):1451–1468, 2023
2023
-
[43]
Global Hölder regularity for the fractional p-Laplacian
Antonio Iannizzotto, Sunra Mosconi, and Marco Squassi na. Global Hölder regularity for the fractional p-Laplacian. Rev. Mat. Iberoam. , 32(4):1353–1392, 2016
2016
-
[44]
Antonio Iannizzotto, Sunra J. N. Mosconi, and Marco Squ assina. Fine boundary regularity for the degenerate fractional p-Laplacian. J. Funct. Anal. , 279(8):108659, 54, 2020
2020
-
[45]
Strong comparison principle for the fract ional p-laplacian and applications to starshaped rings
Sven Jarohs. Strong comparison principle for the fract ional p-laplacian and applications to starshaped rings. Ad- vanced Nonlinear Studies , 18(4):691–704, 2018
2018
-
[46]
Linear and quasilinear elliptic equations
OA Ladyenskaja and NN Ural’ceva. Linear and quasilinear elliptic equations . 1968
1968
-
[47]
A. C. Lazer and P. J. McKenna. On a singular nonlinear ell iptic boundary-value problem. Proc. Amer . Math. Soc. , 111(3):721–730, 1991
1991
-
[48]
Papageorgiou
Salvatore Leonardi and Nikolaos S. Papageorgiou. Posi tive solutions for a class of singular ( p, q)-equations. Adv. Nonlinear Anal., 12(1):Paper No. 20220300, 9, 2023
2023
-
[49]
Lieberman
Gary M. Lieberman. Boundary regularity for solutions o f degenerate elliptic equations. Nonlinear Anal. , 12(11):1203–1219, 1988
1988
-
[50]
Hölder estimates for viscosity solutio ns of equations of fractional p-Laplace type
Erik Lindgren. Hölder estimates for viscosity solutio ns of equations of fractional p-Laplace type. NoDEA Nonlinear Differential Equations Appl. , 23(5):Art. 55, 18, 2016
2016
-
[51]
Kanishka Perera and Elves A. B. Silva. Existence and mul tiplicity of positive solutions for singular quasilinear problems. J. Math. Anal. Appl. , 323(2):1238–1252, 2006
2006
-
[52]
The Dirichlet probl em for the fractional Laplacian: regularity up to the bound- ary .J
Xavier Ros-Oton and Joaquim Serra. The Dirichlet probl em for the fractional Laplacian: regularity up to the bound- ary .J. Math. Pures Appl. (9) , 101(3):275–302, 2014
2014
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