  For $1<p<\infty$, we consider the following problem $$ -\Delta_p u=f(u),\quad
u>0\text{ in }\Omega,\quad\partial_\nu u=0\text{ on }\partial\Omega, $$ where
$\Omega\subset\mathbb R^N$ is either a ball or an annulus. The nonlinearity $f$
is possibly supercritical in the sense of Sobolev embeddings; in particular our
assumptions allow to include the prototype nonlinearity $f(s)=-s^{p-1}+s^{q-1}$
for every $q>p$. We use the shooting method to get existence and multiplicity
of non-constant radial solutions. With the same technique, we also detect the
oscillatory behavior of the solutions around the constant solution $u\equiv1$.
In particular, we prove a conjecture proposed in [D. Bonheure, B. Noris, T.
Weth, {\it Ann. Inst. H. Poincar\'e Anal. Non Lin\'aire} vol. 29, pp. 573-588
(2012)], that is to say, if $p=2$ and $f'(1)>\lambda_{k+1}^{rad}$, there exists
a radial solution of the problem having exactly $k$ intersections with
$u\equiv1$ for a large class of nonlinearities.

Analysis of PDEs