1,720,978 research outputs found

    The Dirichlet problem for possibly singular elliptic equations with degenerate coercivity

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    We deal with existence, uniqueness and regularity of nonnegative solutions to a Dirichlet problem for equations as \begin{equation*} \displaystyle -\operatorname{div}\left(\frac{|\nabla u|^{p-2}\nabla u}{(1+u)^{\theta(p-1)}}\right) = h(u)f \quad \text{in }\Omega, \end{equation*} where Ω\Omega is an open bounded subset of RN\mathbb{R}^N (N2N\ge 2), p>1p>1, θ0\theta\ge 0, f0f\geq 0 belongs to a suitable Lebesgue space and hh is a continuous, nonnegative function which may blow up at zero and it is bounded at infinity.Comment: 37 page

    Elliptic equations with general singular lower order term and measure data

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    Indexed keywords SciVal Topics Metrics Funding details Abstract In this paper we study a nonlinear elliptic boundary value problem with a general singular lower order term, whose model is {-Δu=H(u)μinΩ,u=0on∂Ω,u>0onΩ, where Ω is an open bounded subset of RN, μ is a nonnegative bounded Radon measure on Ω and H is a continuous positive function outside the origin such that lims→0+H(s)=+∞. We do not require any monotonicity property on the singular function H

    Finite energy solutions for nonlinear elliptic equations with competing gradient, singular and L1L^1 terms

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    In this paper we deal with the following boundary value problem \begin{equation*} \begin{cases} -Δ_{p}u + g(u) | \nabla u|^{p} = h(u)f & \text{in ΩΩ,} \newline u\geq 0 & \text{in ΩΩ,} \newline u=0 & \text{on Ω\partial Ω,} \ \end{cases} \end{equation*} in a domain ΩRNΩ\subset \mathbb{R}^{N} (N2)(N \geq 2), where 1p<N1\leq p<N , gg is a positive and continuous function on [0,)[0,\infty), and hh is a continuous function on [0,)[0,\infty) (possibly blowing up at the origin). We show how the presence of regularizing terms hh and gg allows to prove existence of finite energy solutions for nonnegative data ff only belonging to L1(Ω)L^1(Ω)

    Existence and uniqueness results for possibly singular nonlinear elliptic equations with measure data

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    We study existence and uniqueness of solutions to a nonlinear elliptic boundary value problem with a general, and possibly singular, lower order term, whose model is {Δpu=H(u)μin Ω,u>0in Ω,u=0on Ω.\begin{cases} -\Delta_p u = H(u)\mu & \text{in}\ \Omega,\\ u>0 &\text{in}\ \Omega,\\ u=0 &\text{on}\ \partial\Omega. \end{cases} Here Ω\Omega is an open bounded subset of RN\mathbb{R}^N (N2N\ge2), Δpu:=div(up2u)\Delta_p u:= \operatorname{div}(|\nabla u|^{p-2}\nabla u) (1<p<N1<p<N) is the pp-laplacian operator, μ\mu is a nonnegative bounded Radon measure on Ω\Omega and H(s)H(s) is a continuous, positive and finite function outside the origin which grows at most as sγs^{-\gamma}, with γ0\gamma\ge0, near zero

    Finite and Infinite energy solutions of singular elliptic problems: existence and uniqueness

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    We establish existence and uniqueness of solution for the homogeneous Dirichlet problem associated to a fairly general class of elliptic equations modeled by Δu=h(u)f  in Ω, -\Delta u= h(u){f} \ \ \text{in}\,\ \Omega, where ff is an irregular datum, possibly a measure, and hh is a continuous function that may blow up at zero. We also provide regularity results on both the solution and the lower order term depending on the regularity of the data, and we discuss their optimality

    On a singular elliptic equation with a general measure source

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    We prove existence of solutions for a class of singular elliptic problems with a general measure as source term whose model is {-Δu = f(x)/uγ + μ in Ω, u = 0 on ∂Ω, u &gt; 0 on Ω, where Ω is an open bounded subset of RN. Here γ &gt; 0, f is a nonnegative function on Ω, and μ is a nonnegative bounded Radon measure on Ω

    On the behaviour of the first eigenvalue of the pp-Laplacian with Robin boundary conditions as pp goes to 11

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    In this paper we study the Γ\Gamma-limit, as p1p\to 1, of the functional Jp(u)=Ωup+βΩupΩup, J_{p}(u)=\frac{\displaystyle\int_\Omega |\nabla u|^p + \beta\int_{ \partial \Omega} |u|^p}{\displaystyle \int_\Omega |u|^p}, where Ω\Omega is a smooth bounded open set in RN\mathbb R^{N}, p>1p>1 and β\beta is a real number. Among our results, for β>1\beta >-1, we derive an isoperimetric inequality for Λ(Ω,β)=infuBV(Ω),u≢0Du(Ω)+min(β,1)ΩuΩu \Lambda(\Omega,\beta)=\inf_{u \in BV(\Omega), u\not \equiv 0} \frac{\displaystyle |Du|(\Omega) + \min(\beta,1)\int_{ \partial \Omega} |u|}{\displaystyle \int_\Omega |u|} which is the limit as p1+p\to 1^{+} of λ(Ω,p,β)=minuW1,p(Ω)Jp(u). \lambda(\Omega,p,\beta)= \displaystyle \min_{u\in W^{1,p}(\Omega)} J_{p}(u). We show that among all bounded and smooth open sets with given volume, the ball maximizes Λ(Ω,β)\Lambda(\Omega, \beta) when β\beta \in (1,0)(-1,0) and minimizes Λ(Ω,β)\Lambda(\Omega, \beta) when β[0,)\beta \in[0, \infty)

    Behaviour of solutions to pp-Laplacian with Robin boundary conditions as pp goes to 11

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    We study the asymptotic behaviour, as p1+p\to 1^{+}, of the solutions of the following inhomogeneous Robin boundary value problem: \begin{equation} \label{pbabstract} \tag{P} \left\{\begin{array}{ll} \displaystyle -\Delta_p u_p = f & \text{in }\Omega, \displaystyle |\nabla u_p|^{p-2}\nabla u_p\cdot \nu +\lambda |u_p|^{p-2}u_p = g& \text{on } \partial\Omega, \end{array}\right. \end{equation} where Ω\Omega is a bounded domain in RN\mathbb R^{N} with sufficiently smooth boundary, ν\nu is its unit outward normal vector and Δpv\Delta_p v is the pp-Laplacian operator with p>1p>1. The data fLN,(Ω)f\in L^{N,\infty}(\Omega) (which denotes the Marcinkiewicz space) and λ,g\lambda,g are bounded functions defined on Ω\partial\Omega with λ0\lambda\ge0. We find the threshold below which the family of pp--solutions goes to 0 and above which this family blows up. As a second interest we deal with the 11-Laplacian problem formally arising by taking p1+p\to 1^+ in \eqref{pbabstract}
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