Pith. sign in

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 →

arxiv 2411.18505 v2 pith:4LLHLA7I submitted 2024-11-27 math.AP

classification math.AP MSC 35J6035J7535B65
keywords singularellipticequationsmixedlocal-nonlocaloperatorsfractionalq-Laplacianp-LaplacianHölderregularityboundarystrongcomparisonprinciplenonlinearity
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper proves regularity up to the boundary for weak solutions of the mixed local-nonlocal equation $-\Delta_p u+(-\Delta)_q^s u = K_\gamma(x) u^{-\delta}+F(x,u)$ in a bounded smooth domain, with $u=0$ outside the domain and a singular right-hand side. Under the minimal parameter assumption $p>sq$, it shows that for locally bounded data the solution is locally $C^{1,\theta}$; for singular data, the solution is $C^{1,\alpha}$ on the closed domain when $\gamma+\delta<1$ and $C^\alpha$ on the closed domain when $\gamma+\delta>1$. It also proves a strong comparison principle for the singular problem and uses the regularity to obtain existence and uniqueness for sublinear and subcritical perturbations. This matters because earlier work on singular problems for this operator mostly stopped at Sobolev regularity, while boundary Hölder information is what enables comparison arguments, Hopf-type behavior, and multiplicity analysis.

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.

Watch

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

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

  • 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.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 3 minor

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)
  1. [§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.
  2. [§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)
  1. [§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).
  2. [§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.
  3. [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

0 steps flagged · score 0.0 of 10

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 0 free parameters · 7 assumptions · 0 invented entities

The central claims rest on: the standing assumption p > sq; smoothness of Ω and the weight Kγ; imported regularity and comparison results from [2], [20], and [35]; and the additional restrictive assumption q > 1/(1-s) for the strong comparison principle. There are no free parameters fitted to data and no newly postulated physical entities.

assumptions (7)
  • domain assumption p > sq
    Standing assumption of the paper (stated after the Notations section) that ensures the local operator dominates the nonlocal part.
  • domain assumption Ω is a bounded open set with smooth boundary and Kγ is comparable to d^{-γ} in Ω
    Used throughout for boundary regularity, barrier constructions, and the distance function.
  • 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]
    Boundary lower bounds and the perturbative boundary gradient estimates in Theorems 2.3, 2.5, and 2.6 depend on these results.
  • 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)]
    Barrier constructions in Section 3.3.1 and the proof of Theorem 2.5 rely on this estimate.
  • 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
    Used to upgrade local boundedness to interior C^{1,α} regularity in the proof of Theorem 2.2.
  • 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)
    The regularity results are only asserted for solutions satisfying these conditions.
  • ad hoc to paper q > 1/(1-s) for Theorem 2.8
    The strong comparison principle and Lemma 5.4 require this condition, which is more restrictive than the standing assumption p > sq.

how reviews work

0 comments
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.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Regularity results for a class of mixed local and nonlocal singular problems involving distance function

    math.AP 2024-11 conditional novelty 6.0 of 10

    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

52 extracted references · 50 canonical work pages · cited by 1 Pith paper

  1. [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

  2. [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

  3. [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

  4. [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

  5. [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

  6. [5]

    R˘adulescu

    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

  7. [6]

    Multiplicity of solutions for mixed local-nonlocal elliptic equations with singular non - linearity .arXiv preprint, arXiv:2405.05832 , 2024

    Kaushik Bal and Stuti Das. Multiplicity of solutions for mixed local-nonlocal elliptic equations with singular non - linearity .arXiv preprint, arXiv:2405.05832 , 2024

  8. [7]

    Regularity results for a class of mixed local and nonlocal singular problems involving distance function

    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

Show all 52 references
  1. [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

  2. [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

  3. [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

  4. [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

  5. [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

  6. [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

  7. [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

  8. [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

  9. [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

  10. [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

  11. [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

  12. [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

  13. [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

  14. [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

  15. [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

  16. [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

  17. [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

  18. [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

  19. [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...

  20. [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

  21. [28]

    Fulks and J

    W. Fulks and J. S. Maybee. A singular non-linear equatio n. Osaka Math. J. , 12:1–19, 1960

  22. [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

  23. [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

  24. [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

  25. [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

  26. [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

  27. [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

  28. [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

  29. [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

  30. [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

  31. [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

  32. [40]

    Direct methods in the calculus of variations

    Enrico Giusti. Direct methods in the calculus of variations . World Scientific, 2003

  33. [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

  34. [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

  35. [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

  36. [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

  37. [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

  38. [46]

    Linear and quasilinear elliptic equations

    OA Ladyenskaja and NN Ural’ceva. Linear and quasilinear elliptic equations . 1968

  39. [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

  40. [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

  41. [49]

    Lieberman

    Gary M. Lieberman. Boundary regularity for solutions o f degenerate elliptic equations. Nonlinear Anal. , 12(11):1203–1219, 1988

  42. [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

  43. [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

  44. [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

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.