Boundary blow-up solutions and their applications in quasilinear elliptic equations

Based on a comparison principle, we discuss the existence, uniqueness and asymptotic behaviour of various boundary blow-up solutions, for a class of quasilinear elliptic equations, which are then used to obtain a rather complete understanding of some quasilinear elliptic problems on a bounded domain or over the entireR ^N .     

Branches of positive solutions of quasilinear elliptic equations on non-smooth domains

We prove existence of an unbounded global branch (i.e. connected set) of weak solutions of a second order quasilinear equation depending on a real parameter λ$\lambda$ on an arbitrary (possibly non-smooth) bounded domain in R^N${\mathbb{R}}^N$, with a Leray–Lions operator as the leading part. Here, we can allow lower order nonlinearities which depend on first derivatives, satisfying appropriate growth conditions including the critical case. Furthermore, we give sufficient conditions for the existence of a branch consisting entirely of nonnegative solutions for positive λ$\lambda$. Our approach also yields a new existence result in the case of critical growth in derivatives of lower order.     

Structure of least-energy solutions for quasilinear elliptic equations on convex domains

In this paper we study the existence and structure of the least-energy solutions for a class of singularly perturbed quasilinear elliptic equations. Using the moving plane method and a geometric lemma we show that any least-energy solution develops to a single spike-layer solution on convex domains.     

Direct and inverse problems for elliptic equations in cylindrical domains

We consider direct and inverse boundary value problems for elliptic equations in divergence form related to cylindrical domains with a smooth lateral surface. Our basic assumptions is that the differential operator may be represented as a sum of two differential operators in divergence form, the former acting on the «transversal» variables only, the latter on the «axial» one only. Slightly extending well-known abstract results in [4], we can prove an existence-uniqueness and continuous dependence result for the direct problem. This allows to show an existence theorem for the inverse problem, when the additional unknown is a «conductivity» coefficient depending on the axial variable, only.     

Existence of positive solutions of quasilinear degenerate elliptic equations on unbounded domains

Sunto Viene provato un teorema di esistenza di soluzioni positive per una certa classe di equazioni quasilineari ellittiche degeneri su aperti non limitati di Rⁿ utilizzando un metodo di confronta all'infinito.     

环域上一类拟线性椭圆型方程的正径向解的存在性

The existence of positive radial solutions of the equation -din( |Du|p-2Du)=f(u) is studied in annular domains in Rn,n≥2. It is proved that if f(0)≥0, f is somewherenegative in (0,∞), limu→0^ f‘ (u)=0 and limu→∞ (f(u)/u^p-1)=∞, then there is alarge positive radial solution on all annuli. If f(0)≤0 and satisfies certain conditions, then the equation has no radial solution if the annuli are too wide.     

Morrey regularity of solutions to quasilinear elliptic equations over Reifenberg flat domains

We derive global gradient estimates in Morrey spaces for the weak solutions to discontinuous quasilinear elliptic equations related to important variational problems arising in models of linearly elastic laminates and composite materials. The principal coefficients of the quasilinear operator are supposed to be merely measurable in one variable and to have small-BMO seminorms in the remaining orthogonal directions, and the nonlinear terms are subject to controlled growth conditions with respect to the unknown function and its gradient. The boundary of the domain considered is Reifenberg flat which includes boundaries with rough fractal structure. As outgrowth of the main result we get global Hölder continuity of the weak solution with exact value of the corresponding exponent.     

Existence of unbounded positive solutions of quasilinear elliptic equations in two-dimensional exterior domains

In this paper, by using fixed point theory, under quite general conditions on the nonlinear term, we obtain an existence result on unbounded positive solutions of certain quasilinear elliptic equations in two-dimensional exterior domains.     

Existence for bounded positive solutions of quasilinear elliptic equations in two-dimensional exterior domains

In this paper, by using the fixed point theory, we obtain a new existence result for bounded positive solutions of the quasilinear elliptic equations in two-dimensional exterior domains.     

Asymptotic properties of solutions of semilinear second-order elliptic equations in cylindrical domains

The equations under consideration have the following structure:

Entire solutions of quasilinear elliptic equations

We study entire solutions of non-homogeneous quasilinear elliptic equations, with Eqs. (1) and (2) below being typical. A particular special case of interest is the following: Let u be an entire distribution solution of the equation Δpu=|u|^q−1u, where p>1. If q>p−1 then u≡0. On the other hand, if 0<q<p−1 and u(x)=o(|x|^{p/(p−q−1)}) as |x|→∞, then again u≡0. If q=p−1 then u≡0 for all solutions with at most algebraic growth at infinity.     

Multibump solutions for quasilinear elliptic equations

The current paper is concerned with constructing multibump type solutions for a class of quasilinear Schrödinger type equations including the Modified Nonlinear Schrödinger Equations. Our results extend the existence results on multibump type solutions in Coti Zelati and Rabinowitz (1992) [17] to the quasilinear case. Our work provides a theoretic framework for dealing with quasilinear problems, which lack both smoothness and compactness, by using more refined variational techniques such as gluing techniques, Morse theory, Lyapunov–Schmidt reduction, etc.