EN
The focusing nonlinear Schrödinger equation (NLS) with confining harmonic potential
$i∂_t u + 1/2 Δu - 1/2 |x|²u = -|u|^{4/(d-2)}u, x ∈ ℝ^{d}$,
is considered. By modifying a variational technique, we shall give a sufficient condition under which the corresponding solution blows up.