In this paper, we developed a variational framework based on Dirichlet-type energy integrals for the $ \mathrm{p}(\cdot) $-Laplace equation, establishing coercivity and weak lower semicontinuity of the associated functional to guarantee existence and uniqueness of minimizers. The central contribution is a pointwise estimation of weak solutions via fractional truncated potentials, employing Havin–Maz'ya-type nonlinear operators in Herz spaces. Our approach subsumes several earlier results, with classical linear potential estimates recovered as limiting cases.
Citation: Zareen A. Khan, Waqar Afzal, Mujahid Abbas, Daniel Breaz, Luminiţa-Ioana Cotîrlă. Boundedness of truncated Havin–Maz'ya potentials in Herz spaces with applications to $\mathrm{p}(\cdot)$-Laplace equations[J]. AIMS Mathematics, 2026, 11(7): 20677-20710. doi: 10.3934/math.2026841
In this paper, we developed a variational framework based on Dirichlet-type energy integrals for the $ \mathrm{p}(\cdot) $-Laplace equation, establishing coercivity and weak lower semicontinuity of the associated functional to guarantee existence and uniqueness of minimizers. The central contribution is a pointwise estimation of weak solutions via fractional truncated potentials, employing Havin–Maz'ya-type nonlinear operators in Herz spaces. Our approach subsumes several earlier results, with classical linear potential estimates recovered as limiting cases.
| [1] |
O. P. Agrawal, Formulation of Euler–Lagrange equations for fractional variational problems, J. Math. Anal. Appl., 272 (2002), 368–379. http://dx.doi.org/10.1016/S0022-247X(02)00180-4 doi: 10.1016/S0022-247X(02)00180-4
|
| [2] |
C. W. Gear, B. Leimkuhler, G. K. Gupta, Automatic integration of Euler–Lagrange equations with constraints, J. Comput. Appl. Math., 12 (1985), 77–90. http://dx.doi.org/10.1016/0377-0427(85)90008-1 doi: 10.1016/0377-0427(85)90008-1
|
| [3] |
M. Crampin, On the differential geometry of the Euler–Lagrange equations, and the inverse problem of Lagrangian dynamics, J. Phys. A: Math. Gen., 14 (1981), 2567. http://dx.doi.org/10.1088/0305-4470/14/10/012 doi: 10.1088/0305-4470/14/10/012
|
| [4] |
D. Baleanu, J. J. Trujillo, On exact solutions of a class of fractional Euler–Lagrange equations, Nonlinear Dyn., 52 (2008), 331–335. http://dx.doi.org/10.1007/s11071-007-9281-7 doi: 10.1007/s11071-007-9281-7
|
| [5] |
W. Afzal, M. Abbas, W. Hamali, A. M. Mahnashi, M. D. L. Sen, Hermite–Hadamard-type inequalities via Caputo–Fabrizio fractional integral for h-Godunova–Levin and $(h_1, h_2)$-convex functions, Fractal Fract., 7 (2023), 687. http://dx.doi.org/10.3390/fractalfract7090687 doi: 10.3390/fractalfract7090687
|
| [6] |
O. P. Agrawal, Generalized Euler–Lagrange equations and transversality conditions for FVPs in terms of the Caputo derivative, J. Vib. Control, 13 (2007), 1217–1237. https://doi.org/10.1177/1077546307077472 doi: 10.1177/1077546307077472
|
| [7] | J. M. Ball, Minimizers and the Euler-Lagrange equations, In Trends and Applications of Pure Mathematics to Mechanics, Springer, Berlin, Heidelberg, 2005, 1–4. http://dx.doi.org/10.1007/3-540-12916-2_47 |
| [8] |
M. Israr, W. Afzal, S. Ahmad, D. Breaz, L. I. Cotîrlă, Enhancing deep image prior with multiscale attention, SVD pooling, and preconditioned optimizers for image processing, Eur. J. Pure Appl. Math., 18 (2025), 6638. https://doi.org/10.29020/nybg.ejpam.v18i4.6638 doi: 10.29020/nybg.ejpam.v18i4.6638
|
| [9] |
P. J. Rabier, W. C. Rheinboldt, On the numerical solution of the Euler–Lagrange equations, SIAM J. Numer. Anal., 32 (1995), 318–329. http://dx.doi.org/10.1137/0732014 doi: 10.1137/0732014
|
| [10] |
A. Al-Omari, M. H. Alqahtani, Some operators in soft primal spaces, AIMS Math., 9 (2024), 10756–10774. https://doi.org/10.3934/math.2024525 doi: 10.3934/math.2024525
|
| [11] | M. Klimek, Solutions of Euler–Lagrange equations in fractional mechanics, In AIP Conf. Proc., 956 (2007), 73–78. https://doi.org/10.1063/1.2820982 |
| [12] |
R. Groll, S. Jakirlić, C. Tropea, Comparative study of Euler/Euler and Euler/Lagrange approaches simulating evaporation in a turbulent gas–liquid flow, Int. J. Numer. Meth. Fluids, 59 (2009), 873–906. http://dx.doi.org/10.1002/fld.1914 doi: 10.1002/fld.1914
|
| [13] |
A. Adrees, W. Afzal, K. Shabbir, N. M. Dahshan, A. E. Abuzeid, R. A. Tahir, et al., On some properties and integral inequalities for modified (p, h)-convex stochastic processes, Open J. Math. Sci., 10 (2026), 477–491. https://doi.org/10.30538/oms2026.0300 doi: 10.30538/oms2026.0300
|
| [14] |
A. Sokolichin, G. Eigenberger, A. Lapin, A. Lübert, Dynamic numerical simulation of gas-liquid two-phase flows Euler/Euler versus Euler/Lagrange, Chem. Eng. Sci., 52 (1997), 611–626. http://dx.doi.org/10.1016/S0009-2509(96)00480-8 doi: 10.1016/S0009-2509(96)00480-8
|
| [15] |
M. A. Herzallah, D. Baleanu, Fractional-order Euler–Lagrange equations and formulation of Hamiltonian equations, Nonlinear Dyn., 58 (2009), 385–391. http://dx.doi.org/10.1007/s11071-009-9561-5 doi: 10.1007/s11071-009-9561-5
|
| [16] |
Z. A. Khan, W. Afzal, M. Abbas, J. Ro, A. A. Zaagan, Some well known inequalities on two dimensional convex mappings by means of pseudo L-R interval order relations via fractional integral operators having non-singular kernel, AIMS Math., 9 (2024), 16061–16092. https://doi.org/10.3934/math.2024778 doi: 10.3934/math.2024778
|
| [17] |
Z. Y. Li, J. L. Fu, L. Q. Chen, Euler–Lagrange equation from nonlocal-in-time kinetic energy of nonconservative system, Phys. Lett. A, 374 (2009), 106–109. http://dx.doi.org/10.1016/j.physleta.2009.10.080 doi: 10.1016/j.physleta.2009.10.080
|
| [18] |
S. Balachandar, Lagrangian and Eulerian drag models that are consistent between Euler–Lagrange and Euler–Euler (two-fluid) approaches for homogeneous systems, Phys. Rev. Fluids, 5 (2020), 084302. http://dx.doi.org/10.1103/PhysRevFluids.5.084302 doi: 10.1103/PhysRevFluids.5.084302
|
| [19] |
W. Afzal, Boundedness and regularity of the Navier–Stokes system in generalized Herz spaces via a novel fractional potential framework, Chaos Soliton. Fract., 201 (2025), 117086. http://dx.doi.org/10.1016/j.chaos.2025.117086 doi: 10.1016/j.chaos.2025.117086
|
| [20] |
I. A. Kogan, P. J. Olver, Invariant Euler–Lagrange equations and the invariant variational bicomplex, Acta Appl. Math., 76 (2003), 137–193. http://dx.doi.org/10.1023/A:1021781304548 doi: 10.1023/A:1021781304548
|
| [21] |
O. Alghamdi, A. Al-Omari, M. H. Alqahtani, Novel operators in the frame of primal topological spaces, AIMS Math., 9 (2024), 25792–25808. https://doi.org/10.3934/math.20241260 doi: 10.3934/math.20241260
|
| [22] |
C. Pérez, On sufficient conditions for the boundedness of the Hardy-Littlewood maximal operator between weighted $L^p$-spaces with different weights, Proc. London Math. Soc., 71 (1995), 135–157. http://dx.doi.org/10.1112/plms/s3-71.1.135 doi: 10.1112/plms/s3-71.1.135
|
| [23] |
W. Reichel, Characterization of balls by Riesz-potentials, Ann. Mat. Pura Appl., 188 (2009), 235–245. http://dx.doi.org/10.1007/s10231-008-0073-6 doi: 10.1007/s10231-008-0073-6
|
| [24] |
W. Afzal, Regularity of parabolic Ornstein–Uhlenbeck equations via boundedness of fractional Muckenhoupt-type weighted singular operators in variable Herz spaces, J. Pseudo-Differ. Oper. Appl., 17 (2026), 2. http://dx.doi.org/10.1007/s11868-025-00685-w doi: 10.1007/s11868-025-00685-w
|
| [25] |
J. G. Bak, Sharp estimates for the Bochner-Riesz operator of negative order in $\mathbb{R}^2$, Proc. Amer. Math. Soc., 125 (1997), 1977–1986. http://dx.doi.org/10.1090/S0002-9939-97-03723-4 doi: 10.1090/S0002-9939-97-03723-4
|
| [26] |
W. Afzal, A note on the boundedness of the Wolff potential on complete noncompact manifolds in Zygmund spaces, Open J. Math. Anal., 10 (2026), 215–219. https://doi.org/10.30538/psrp-oma2026.0199 doi: 10.30538/psrp-oma2026.0199
|
| [27] |
A. Almeida, P. Harjulehto, P. Hästö, T. Lukkari, Riesz and Wolff potentials and elliptic equations in variable exponent weak Lebesgue spaces, Ann. Mat. Pura Appl., 194 (2015), 405–424. http://dx.doi.org/10.1007/s10231-014-0398-9 doi: 10.1007/s10231-014-0398-9
|
| [28] |
M. Borowski, I. Chlebicka, B. Miasojedow, Boundedness of Wolff-type potentials and applications to PDEs, Nonlinear Anal. Real World Appl., 76 (2024), 104025. http://dx.doi.org/10.1016/j.nonrwa.2023.104025 doi: 10.1016/j.nonrwa.2023.104025
|
| [29] | V. G. Maz'ya, V. P. Havin, A nonlinear potential theory, Uspehi Mat. Nauk, 27 (1972), 67–138. |
| [30] |
D. Cardona, M. Ruzhansky, Boundedness of pseudo-differential operators in subelliptic Sobolev and Besov spaces on compact Lie groups, Complex Var. Elliptic Equ., 69 (2024), 1049–1082. https://doi.org/10.1080/17476933.2023.2196416 doi: 10.1080/17476933.2023.2196416
|
| [31] |
R. Korte, T. Kuusi, A note on the Wolff potential estimate for solutions to elliptic equations involving measures, Adv. Calc. Var., 3 (2010), 99–113. http://dx.doi.org/10.1515/ACV.2010.005 doi: 10.1515/ACV.2010.005
|
| [32] |
J. Malý, Wolff potential estimates of superminimizers of Orlicz type Dirichlet integrals, Manuscripta Math., 110 (2003), 513–525. http://dx.doi.org/10.1007/s00229-003-0358-4 doi: 10.1007/s00229-003-0358-4
|
| [33] |
T. Lukkari, F. Y. Maeda, N. Marola, Wolff potential estimates for elliptic equations with nonstandard growth and applications, Forum Math., 22 (2010), 1061–1087. http://dx.doi.org/10.1515/FORUM.2010.057 doi: 10.1515/FORUM.2010.057
|
| [34] |
M. Abbas, W. Afzal, T. Botmart, A. M. Galal, Jensen, Ostrowski and Hermite–Hadamard type inequalities for h-convex stochastic processes by means of center-radius order relation, AIMS Math., 8 (2023), 16013–16030. https://doi.org/10.3934/math.2023817 doi: 10.3934/math.2023817
|
| [35] |
P. Baroni, Riesz potential estimates for a general class of quasilinear equations, Calc. Var. Partial Dif., 53 (2015), 803–846. http://dx.doi.org/10.1007/s00526-014-0782-y doi: 10.1007/s00526-014-0782-y
|
| [36] |
I. Chlebicka, Y. Youn, A. Zatorska-Goldstein, Wolff potentials and measure data vectorial problems with Orlicz growth, Calc. Var. Partial Dif., 62 (2023), 64. http://dx.doi.org/10.1007/s00526-022-02402-7 doi: 10.1007/s00526-022-02402-7
|
| [37] |
G. Cupini, P. Marcellini, E. Mascolo, Local boundedness of weak solutions to elliptic equations with $p, q$-growth, Math. Eng., 5 (2023), 1–28. http://dx.doi.org/10.3934/mine.2023065 doi: 10.3934/mine.2023065
|
| [38] |
G. Mingione, Gradient estimates below the duality exponent, Math. Ann., 346 (2010), 571–627. http://dx.doi.org/10.1007/s00208-009-0421-2 doi: 10.1007/s00208-009-0421-2
|
| [39] |
R. O'Neil, Convolution operators and $L(p, q)$ spaces, Duke Math. J., 30 (1963), 129–142. http://dx.doi.org/10.1215/S0012-7094-63-03015-1 doi: 10.1215/S0012-7094-63-03015-1
|
| [40] |
G. Peetre, Espaces d'interpolation, généralisations, applications, Rend. Sem. Mat. Fis. Milano, 34 (1964), 133–164. https://doi.org/10.1007/BF02923402 doi: 10.1007/BF02923402
|
| [41] |
W. Afzal, M. Abbas, M. Z. Meetei, S. Bourazza, Tensorial Maclaurin approximation bounds and structural properties for mixed-norm Orlicz–Zygmund spaces, Mathematics, 13 (2025), 917. https://doi.org/10.3390/math13060917 doi: 10.3390/math13060917
|
| [42] |
M. Kim, K. A. Lee, S. C. Lee, Wolff potential estimates and Wiener criterion for nonlocal equations with Orlicz growth, J. Funct. Anal., 288 (2025), 110690. http://dx.doi.org/10.1016/j.jfa.2024.110690 doi: 10.1016/j.jfa.2024.110690
|
| [43] |
A. M. Abd El-latif, M. H. Alqahtani, F. A. Gharib, Strictly wider class of soft sets via supra soft $\delta$-closure operator, Int. J. Anal. Appl., 22 (2024), 47. https://doi.org/10.28924/2291-8639-22-2024-47 doi: 10.28924/2291-8639-22-2024-47
|
| [44] |
J. Maas, J. van Neerven, Boundedness of Riesz transforms for elliptic operators on abstract Wiener spaces, J. Funct. Anal., 257 (2009), 2410–2475. http://dx.doi.org/10.1016/j.jfa.2009.07.001 doi: 10.1016/j.jfa.2009.07.001
|
| [45] |
V. S. Guliyev, F. Deringoz, On the Riesz potential and its commutators on generalized Orlicz-Morrey spaces, J. Funct. Spaces, 2014 (2014), 617414. http://dx.doi.org/10.1155/2014/617414 doi: 10.1155/2014/617414
|
| [46] |
J. Wu, Boundedness for Riesz-type potential operators on Herz-Morrey spaces with variable exponent, Math. Inequal. Appl., 18 (2015), 471–484. http://dx.doi.org/10.7153/mia-18-35 doi: 10.7153/mia-18-35
|
| [47] |
H. Rafeiro, S. Samko, Riesz potential operator in continual variable exponents Herz spaces, Math. Nachr., 288 (2015), 465–475. http://dx.doi.org/10.1002/mana.201300270 doi: 10.1002/mana.201300270
|
| [48] |
H. Ahmad, M. Tariq, A. Asghar, W. Afzal, M. Aphane, R. Efendiev, Some new notions of mathematical integral inequalities: Theory and applications, Int. J. Anal. Appl., 24 (2026), 175. https://doi.org/10.28924/2291-8639-24-2026-175 doi: 10.28924/2291-8639-24-2026-175
|
| [49] |
Z. A. Ameen, M. H. Alqahtani, Baire category soft sets and their symmetric local properties, Symmetry, 15 (2023), 1810. https://doi.org/10.3390/sym15101810 doi: 10.3390/sym15101810
|
| [50] |
W. Afzal, M. Abbas, D. Breaz, L. I. Cotîrlă, Fractional Hermite–Hadamard, Newton–Milne, and convexity involving arithmetic–geometric mean-type inequalities in Hilbert and mixed-norm Morrey spaces $\ell_{q(\cdot)}(M_{p(\cdot), v(\cdot)})$ with variable exponents, Fractal Fract., 8 (2024), 518. http://dx.doi.org/10.3390/fractalfract8090518 doi: 10.3390/fractalfract8090518
|
| [51] |
Y. Sawano, T. Shimomura, Sobolev embeddings for Riesz potentials of functions in Musielak–Orlicz–Morrey spaces over non-doubling measure spaces, Integr. Transf. Spec. F., 25 (2014), 976–991. http://dx.doi.org/10.1080/10652469.2014.955099 doi: 10.1080/10652469.2014.955099
|
| [52] |
T. Ohno, T. Shimomura, Generalized Riesz potential operators on Musielak–Orlicz–Morrey spaces over unbounded metric measure spaces, Anal. Math. Phys., 15 (2025), 24. http://dx.doi.org/10.1007/s13324-024-01004-2 doi: 10.1007/s13324-024-01004-2
|
| [53] |
H. Aimar, S. Hartzstein, B. Iaffei, B. Viviani, The Riesz potential as a multilinear operator into general ${\rm{BMO}}_\beta$ spaces, J. Math. Sci., 173 (2011), 643–655. http://dx.doi.org/10.1007/s10958-011-0261-4 doi: 10.1007/s10958-011-0261-4
|
| [54] |
W. Afzal, M. Abbas, M. Tariq, J. E. Mac, H. Ahmad, A note on the boundedness of the multidimensional Katugampola operator in Campanato spaces, Gulf J. Math., 23 (2026), 1. https://doi.org/10.56947/5e9waj50 doi: 10.56947/5e9waj50
|
| [55] |
J. J. Hasanov, R. Ayazoglu, S. Bayrakci, B-maximal commutators, commutators of B-singular integral operators and B-Riesz potentials on B-Morrey spaces, Open Math., 18 (2020), 715–730. http://dx.doi.org/10.1515/math-2020-0033 doi: 10.1515/math-2020-0033
|
| [56] | V. I. Burenkov, Recent progress in studying the boundedness of classical operators of real analysis in general Morrey-type spaces. I, Eurasian Math. J., 3 (2012), 11–32. |
| [57] |
A. Al-Omari, M. H. Alqahtani, Primal structure with closure operators and their applications, Mathematics, 11 (2023), 4946. https://doi.org/10.3390/math11244946 doi: 10.3390/math11244946
|
| [58] |
B. Sultan, F. Azmi, M. Sultan, M. Mehmood, N. Mlaiki, Boundedness of Riesz potential operator on grand Herz-Morrey spaces, Axioms, 11 (2022), 583. http://dx.doi.org/10.3390/axioms11110583 doi: 10.3390/axioms11110583
|
| [59] |
W. Afzal, M. Abbas, N. M. Aloraini, J. Ro, Resolution of open problems via Orlicz-Zygmund spaces and new geometric properties of Morrey spaces in the Besov sense with non-standard growth, AIMS Math., 10 (2025), 13908–13940. http://dx.doi.org/10.3934/math.2025630 doi: 10.3934/math.2025630
|
| [60] |
M. H. Alqahtani, A. M. Abd El-latif, Separation axioms via novel operators in the frame of topological spaces and applications, AIMS Math., 9 (2024), 14213–14227. https://doi.org/10.3934/math.2024690 doi: 10.3934/math.2024690
|
| [61] |
W. Afzal, M. Abbas, J. E. Macías-Díaz, A. Gallegos, Y. Almalki, Boundedness and Sobolev-type estimates for the exponentially damped Riesz potential with applications to the regularity theory of elliptic PDEs, Fractal Fract., 9 (2025), 458. http://dx.doi.org/10.3390/fractalfract9070458 doi: 10.3390/fractalfract9070458
|
| [62] |
M. Izuki, Boundedness of sublinear operators on Herz spaces with variable exponent and application to wavelet characterization, Anal. Math., 36 (2010), 33–50. http://dx.doi.org/10.2478/s11533-009-0057-9 doi: 10.2478/s11533-009-0057-9
|
| [63] |
X. Li, D. Yang, Boundedness of some sublinear operators on Herz spaces, Illinois J. Math., 40 (1996), 484–501. http://dx.doi.org/10.1215/ijm/1255986021 doi: 10.1215/ijm/1255986021
|
| [64] |
A. Almeida, D. Drihem, Maximal, potential and singular type operators on Herz spaces with variable exponents, J. Math. Anal. Appl., 394 (2012), 781–795. http://dx.doi.org/10.1016/j.jmaa.2012.03.059 doi: 10.1016/j.jmaa.2012.03.059
|
| [65] |
W. Afzal, M. Abbas, M. Tariq, E. Hincal, W. M. Abdelfattah, Sharp boundedness criteria for the Wolff potential on complete Riemannian manifolds, Int. J. Math. Comput. Sci., 21 (2026), 519–526. https://doi.org/10.69793/ijmcs/02.2026/khan doi: 10.69793/ijmcs/02.2026/khan
|
| [66] |
D. Drihem, F. Seghiri, Notes on the Herz-type Hardy spaces of variable smoothness and integrability, Math. Inequal. Appl., 19 (2016), 145–165. http://dx.doi.org/10.7153/mia-19-11 doi: 10.7153/mia-19-11
|
| [67] | R. A. Adams, J. J. F. Fournier, Sobolev spaces, 2nd ed., Academic Press, Amsterdam, 2003. |
| [68] |
P. Harjulehto, P. Hästö, Sobolev inequalities for variable exponents attaining the values 1 and $n$, Publ. Mat., 52 (2008), 347–363. http://dx.doi.org/10.5565/PUBLMAT_52108_17 doi: 10.5565/PUBLMAT_52108_17
|
| [69] | L. Diening, P. Harjulehto, P. Hästö, M. Ruzicka, Lebesgue and Sobolev spaces with variable exponents, Springer, Heidelberg, 2011. https://doi.org/10.1007/978-3-642-18363-8 |
| [70] | M. R. Ebert, U. Kähler, I. Sabadini, J. Toft (Eds.), New tools in mathematical analysis and applications: Proceedings of the 14th ISAAC Congress 2023, Ribeirão Preto, Brazil, Springer Nature Switzerland, 2025. |
| [71] |
W. Afzal, M. Abbas, O. M. Alsalami, Bounds of different integral operators in tensorial Hilbert and variable exponent function spaces, Mathematics, 12 (2024), 2464. http://dx.doi.org/10.3390/math12162464 doi: 10.3390/math12162464
|
| [72] |
M. Nasir, A. Raza, L. I. Cotîrlă, D. Breaz, Boundedness of Bessel–Riesz operator in variable Lebesgue measure spaces, Mathematics, 13 (2025), 410. http://dx.doi.org/10.3390/math13030410 doi: 10.3390/math13030410
|