Qualitative properties and existence of sign changing solutions with compact support for an equation with a p-Laplace operator

We consider radial solutions of an elliptic equation involving the p-Laplace operator and prove by a shooting method the existence of compactly supported solutions with any prescribed number of nodes. The method is based on a change of variables in the phase plane corresponding to an asymptotic Hamiltonian system and provides qualitative properties of the solutions

Highly oscillatory solutions of a Neumann problem for a pp-laplacian equation

We deal with a boundary value problem of the form $-\epsilon(\phi_p(\epsilon u'))'+a(x)W'(u)=0,\quad u'(0)=0=u'(1),$ where $\phi_p(s) = \vert s \vert^{p-2} s$ for $s \in \mathbb{R}$ and $p>1$, and $W:[-1,1] \to {\mathbb R}$ is a double-well potential. We study the limit profile of solutions when $\epsilon \to 0^+$ and, conversely, we prove the existence of nodal solutions associated with any admissible limit profile when $\epsilon$ is small enough

Splitting the Fučík Spectrum and the Number of Solutions to a Quasilinear ODE

For $\varnothing$ an increasing homeomorphism from $\mathbb{R}$ onto $\mathbb{R}$ and $f\epsilon C\left(\mathbb{R}\right)$, we consider the problem $$\left(\varnothing\left(u'\right)\right)'+f\left(u\right)=0,\qquad t\epsilon\left(0,L\right),\qquad u\left(0\right)=0=u\left(L\right).$$ The aim is to study multiplicity of solutions by means of some generalized Pseudo Fu$\check{\textrm{c}}$ik spectrum (at infinity, or at zero). New insights that lead to a very precise counting of solutions are obtained by splitting these spectra into two parts, called Positive Pseudo Fu$\check{\textrm{c}}$ik Spectrum (PPFS) and Negative Pseudo Fu$\check{\textrm{c}}$ik spectrum (NPFS) (at infinity, or at zero, respectively), in this form tue can discuss separately the two cases u' (0) > 0 and u' (0) < 0

Existence of positive solutions of a superlinear boundary value problem with indefinite weight

We deal with the existence of positive solutions for a two-point boundary value problem associated with the nonlinear second order equation $u''+a(x)g(u)=0$. The weight $a(x)$ is allowed to change its sign. We assume that the function $g\colon\mathopen{[}0,+\infty\mathclose{[}\to\mathbb{R}$ is continuous, $g(0)=0$ and satisfies suitable growth conditions, so as the case $g(s)=s^{p}$, with $p>1$, is covered. In particular we suppose that $g(s)/s$ is large near infinity, but we do not require that $g(s)$ is non-negative in a neighborhood of zero. Using a topological approach based on the Leray-Schauder degree we obtain a result of existence of at least a positive solution that improves previous existence theorems.Comment: 12 pages, 4 PNG figure