Title: Pohozaev identity for the fractional $p-$Laplacian on $\mathbb{R}^N$,
Abstract: By virtue of a suitable approximation argument, we prove a Pohozaev identity
for nonlinear nonlocal problems on $\mathbb{R}^N$ involving the fractional
$p-$Laplacian operator. Furthermore we provide an application of the identity
to show that some relevant levels of the energy functional associated with the
problem coincide.