RT Journal Article T1 Failure of the strong maximum principle for linear elliptic with singular convection of non-negative divergence A1 Boccardo, L. A1 Gómez Castro, David A1 Díaz Díaz, Jesús Ildefonso AB In this paper we study existence, uniqueness, and integrability of solutions to the Dirichlet problem −div(M(x)∇u)=−div(E(x)u)+f in a bounded domain of RN with N≥3. We are particularly interested in singular E with divE≥0. We start by recalling known existence results when |E|∈LN that do not rely on the sign of divE. Then, under the assumption that divE≥0 distributionally, we extend the existence theory to |E|∈L2. For the uniqueness, we prove a comparison principle in this setting. Lastly, we discuss the particular cases of E singular at one point as Ax/|x|2, or towards the boundary as divE∼dist(x,∂Ω)−2−α. In these cases the singularity of E leads to u vanishing to a certain order. In particular, this shows that the strong maximum principle fails in the presence of such singular drift terms E. YR 2022 FD 2022-11-21 LK https://hdl.handle.net/20.500.14352/72748 UL https://hdl.handle.net/20.500.14352/72748 LA eng NO [1] L. Boccardo. Some developments on Dirichlet problems with discontinuous coefficients. Bolletino dell Unione Matematica Italiana, 2(1):285–297, 2009.[2] L. Boccardo: Dirichlet problems with singular convection term and applications; J. Differential Equations 258 (2015), 2290-2314.[3] L. Boccardo: The impact of the zero order term in the study of Dirichlet problems with convection or drift terms. Revista Matemática Complutense https://doi.org/10.1007/s13163-022-00434-1[4] L. Boccardo, T. Gallouët, Nonlinear elliptic equations with right hand side measures; Comm. Partial Differential Equations, 17 (1992), 641–655.[5] L. Boccardo and L. Orsina. Very singular solutions for linear Dirichlet problems with singular convection terms. Nonlinear Analysis, 2019.[6] L. Boccardo, L. Orsina, M.M. Porzio: Regularity results and asymptotic behavior for a noncoercive parabolic problem; J. Evol. Equ. 21 (2021), 2195-2211.[7] H. Brezis, T. Cazenave, Y. Martel and A. Ramiandrisoa, Blow up for ut − 2206u = g(u) revisited, Advances in Diff. Eq., 1 (1996), 73–90.[8] H. Brezis and W. Strauss, Semilinear second order elliptic equations in L1, J. Math.Soc. Japan 25 (1974), 831-844.[9] J.I. Díaz, Nonlinear Partial Differential Equations and Free Boundaries. Pitman, London, 1985.[10] J.I. Díaz, On the ambiguous treatment of the Schrödinger equation for the infinite potential well and an alternative via singular potentials: the multi-dimensional case. SeMA-Journal 74 3 (2017) 225-278[11] J.I. Díaz, Correction to: On the ambiguous treatment of the Schrödinger equation for the infinite potential well and an alternative via singular potentials: the multi-dimensional case. SeMA-Journal 75 (2018), no. 3, 563–568[12] J. I. Díaz, D. Gómez-Castro, and J.-M. Rakotoson. Existence and uniqueness of solutions of Schrödinger type stationary equations with very singular potentials without prescribing boundary conditions and some applications. Differential Equations & Applications, 10(1):47–74, 2018.[13] J. I. Díaz, D. Gómez-Castro, J. M. Rakotoson, and R. Temam. Linear diffusion with singular absorption potential and/or unbounded convective flow: The weighted space approach. Discrete and Continuous Dynamical Systems, 38(2):509–546, 2018.[14] J. I. Díaz, D. Gómez-Castro, and J. L. Vázquez. The fractional Schrödinger equation with general nonnegative potentials. The weighted space approach. Nonlinear Analysis, 177:325– 360, 2018.[15] D. Gilbarg and N.S. Trudinger. Elliptic Partial Differential Equations of Second Order, Springer-Verlag, New York, 1977.[16] D. Gómez-Castro and J. L. Vázquez. The fractional Schrödinger equation with singular potential and measure data. Discrete & Continuous Dynamical Systems - A, 39(12):7113–7139, 2019.[17] L. Orsina and A. C. Ponce. Hopf potentials for Schroedinger operators, Anal PDE 11(8), 2015–2047 (2018).[18] G. Stampacchia: Le probléme de Dirichlet pour les equations elliptiques du second ordre a coefficients discontinus. Ann. Inst. Fourier (Grenoble) 15 (1965) 189-258. NO Unión Europea. Horizonte 2020 NO Ministerio de Ciencia e Innovación (MICINN) NO Universidad Complutense de Madrid (UCM) DS Docta Complutense RD 3 may 2024