Existence results for nonlinear Fourier problems with variable exponent growth
DOI: https://doi.org/10.3846/mma.2026.25157Abstract
We study nonlinear problems which use the generalized $\alpha(x)-$Laplacian operator under Fourier boundary conditions with $L^{1}$ data. Our research establishes both weak and entropy solutions through the framework of variable exponent Sobolev spaces. Our solution method uses monotone operator theory and appropriate approximation methods to develop a unified approach for dealing with nonlinearities that exhibit variable growth. These findings help expand knowledge about nonlinear Fourier-type problems while demonstrating how entropy formulations enable well-posedness for problems with minimal data requirements.
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Lebesgue and Sobolev spaces with variable exponent, Fourier boundary conditions, weak solutions, entropy solution, nonlinear elliptic problemsHow to Cite
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References
A. Aberqi, J. Bennouna, O. Benslimane and M.A. Ragusa. Existence results for double phase problem in Sobolev–Orlicz spaces with variable exponents in complete manifold. Mediterr. J. Math., 19(4):158, 2022. https://doi.org/10.1007/s00009-022-02097-0
A. Aberqi, J. Bennouna, O. Benslimane and M.A. Ragusa. Weak solvability of nonlinear elliptic equations involving variable exponents. Discrete Contin. Dyn. Syst. Ser. S, 16(6):1142–1157, 2023. https://doi.org/10.3934/dcdss.2022105
F. Andreu, N. Igbida, J.M. Mazón and J. Toledo. l1 existence and uniqueness results for quasi-linear elliptic equations with nonlinear boundary conditions. Ann. Inst. H. Poincaré Anal. Non Linéaire, 24(1):61–89, 2007. https://doi.org/10.1016/j.anihpc.2005.09.009
F. Andreu, J.M. Mazón, S. Segura De Léon and J. Toledo. Quasi-linear elliptic and parabolic equations in l1 with nonlinear boundary conditions. Adv. Math. Sci. Appl., 7:183–213, 1997.
S. Antontsev and J.F. Rodrigues. On stationary thermorheological viscous flows. Ann. Univ. Ferrara Sez. VII Sci. Mat., 52(1):19–36, 2006. https://doi.org/10.1007/s11565-006-0002-9
E. Azroul, M.B. Benboubker and S. Ouaro. Entropy solution for some p(x)-quasilinear problem with right-hand side measure. Afr. Diaspora J. Math., 13(2):23–44, 2012.
E. Azroul, H. Redwane and C. Yazough. Strongly nonlinear nonhomogeneous elliptic unilateral problems with l1 data and no sign conditions. Electron. J. Differ. Equ., 2012(79):1–20, 2012.
M.B. Benboubker, E. Azroul and A. Barbara. Quasilinear elliptic problems with nonstandard growth. Electron. J. Differ. Equ., 2011(62):1–16, 2011.
M. Bendahmane and P. Wittbold. Renormalized solutions for nonlinear elliptic equations with variable exponents and l1-data. Nonlinear Anal., 70(2):567–583, 2009. https://doi.org/10.1016/j.na.2007.12.027
P. Bénilan, L. Boccardo, T. Gallouët, R. Gariepy, M. Pierre and J.L. Vazquez. An l1 theory of existence and uniqueness of solutions of non linear elliptic equations. Ann. Sc. Norm. Super. Pisa Cl. Sci., 22(2):241–273, 1995.
Y. Chen, S. Levine and M. Rao. Variable exponent, linear growth functionals in image restoration. SIAM J. Appl. Math., 66(4):1383–1406, 2006. https://doi.org/10.1137/050624522.
L. Diening. Riesz potential and Sobolev embeddings on generalized Lebesgue and Sobolev spaces lp(·) and wk,p(·). Math. Nachr., 268:31–43, 2004. https://doi.org/10.1002/mana.200310157
L. Diening, P. Harjulehto, P. Hästö and M. Ružička. Lebesgue and Sobolev Spaces with Variable Exponents. Lecture Notes in Mathematics. Springer-Verlag, Heidelberg, 2011.
X.L. Fan. Boundary trace embedding theorems for variable exponent Sobolev spaces. J. Math. Anal. Appl., 339:1395–1412, 2008. https://doi.org/10.1016/j.jmaa.2007.08.003
X.L. Fan and D. Zhao. On the generalised Orlicz–Sobolev space wk,p(x)(ω). J. Gansu Educ. Coll., 12(1):1–6, 1998.
P.R. Halmos. Measure Theory. D. Van Nostrand, Springer-Verlag, New York, 1974.
A.S. Kamaletdinov, L.M. Kozhevnikova and L.Y. Melnik. Existence of solutions of anisotropic elliptic equations with variable exponent in unbounded domains. Lobachevskii J. Math., 39(2):224–235, 2018. https://doi.org/10.1134/s1995080218020166
A. Kristly, V.D. Radulescu and C. Varga. Variational principles in mathematical physics, geometry, and economics: qualitative analysis of nonlinear equations and unilateral problems, volume 136 of Encyclopedia of Mathematics and its Applications. Cambridge University Press, Cambridge, 2010.
J.L. Lions. Quelques méthodes de résolution des problèmes aux limites non linéaires. Dunod, 1969.
I. Nyanquini and S. Ouaro. Entropy solution for nonlinear elliptic problem involving variable exponent and Fourier type boundary-value condition. Afr. Mat., 23(2):205–228, 2012. https://doi.org/10.1007/s13370-011-0030-1
S. Ouaro and S. Soma. Weak and entropy solutions to nonlinear Neumann boundary-value problems with variable exponents. Complex Var. Elliptic Equ., 56(7-9):829–851, 2011. https://doi.org/10.1080/17476933.2010.504840
S. Ouaro and A. Tchousso. Well-posedness result for a nonlinear elliptic problem involving variable exponent and Robin type boundary condition. Afr. Diaspora J. Math., 11(2):36–64, 2011.
K.R. Rajagopal and M. Ruzicka. Mathematical modeling of electrorheological materials. Contin. Mech. Thermodyn., 13(1):59–78, 2001. https://doi.org/10.1007/s001610100034
A. Sabiry, S. Melliani and A. Kassidi. Certain regularity results of p(x)parabolic problems with measure data. Asia Pac. J. Math., 10:1, 2023. https://doi.org/10.28924/APJM/10-1
M. Sanchon and J.M. Urbano. Entropy solutions for the p(x)Laplace equation. Trans. Amer. Math. Soc., 361(12):6387–6405, 2009. https://doi.org/10.1090/s0002-9947-09-04399-2
L.L. Wang, Y.H. Fan and W.G. Ge. Existence and multiplicity of solutions for a Neumann problem involving the p(x)-Laplace operator. Nonlinear Anal., 71(9):4259–4270, 2009. https://doi.org/10.1016/j.na.2009.02.116
J. Yao. Solutions for Neumann boundary value problems involving p(x)-Laplace operators. Nonlinear Anal., 68(5):1271–1283, 2008. https://doi.org/10.1016/j.na.2006.12.020
V.V. Zhikov. Averaging of functionals of the calculus of variations and elasticity theory. Math. USSR Izvestiya, 29(1):33–66, 1987. https://doi.org/10.1070/im1987v029n01abeh000958
V.V. Zhikov. Meyer-type estimates for solving the nonlinear Stokes system. Differ. Uravn., 33(1):107–114, 1997.
G. Zineddaine, A. Sabiry, S. Melliani and A. Kassidi. Existence results in weighted Sobolev space for quasilinear degenerate p(z)-elliptic problems with a Hardy potential. Math. Model. Anal., 29(3):460–479, 2024. https://doi.org/10.3846/mma.2024.18696
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Copyright (c) 2026 The Author(s). Published by Vilnius Gediminas Technical University.
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