  Application of the adS/CFT correspondence to the RS models may predict that
there is no static solution for black holes with a radius larger than the bulk
curvature scale. When the black hole has an extremal horizon, however, the
correspondence suggests that the black hole can stay static. We focus on the
effects of cosmological constant on the brane on such extremal brane-localized
black holes. We observe that the positive cosmological constant restrict the
black hole size on the brane as in ordinary four-dimensional general
relativity. The maximum black hole size differs from that in four-dimensional
general relativity case due to the non-linear term in the effective Einstein
equation. In the negative cosmological constant case, we obtain an implication
on the Newton constant in the Karch-Randall model.
