  We devote this paper to study semi-stable nonconstant radial solutions of
$S_k(D^2u) = w(|x|)g(u)$ on the Euclidean space $R^n$. We establish pointwise
estimates and necessary conditions for the existence of such solutions (not
necessarily bounded) for this equation. For bounded solutions we estimate their
asymptotic behavior at infinity. All the estimates are given in terms of the
spatial dimension $n$, the values of $k$ and the behavior at infinity of the
growth rate function of $w$.
