 Projective Nullstellensatz

Let $I\subseteq k[x_0,\dots ,x_n]$ be a homogeneous ideal over an algebraically closed field, and letbe the irrelevant ideal. Then $V_{+}(I)=\varnothing$ exactly when either $I=(1)$ or $\sqrt{I}=\mathfrak{m}$. For a proper homogeneous ideal this is also equivalent to ${\mathfrak{m}}^N\subseteq I$ for some $N$.