Emergent AdS3 in the zero entropy extremal black holes

We investigate the zero entropy limit of the near horizon geometries of D = 4 and D = 5 general extremal black holes with \( {\text{SL}}\left( {2,\mathbb{R}} \right) \times {\text{U}}{(1)^{D - 3}} \) symmetry. We derive some conditions on the geometries from expectation of regularity. We then show that an AdS3 structure emerges in a certain scaling limit, though the periodicity shrinks to zero. We present some examples to see the above concretely. We also comment on some implications to the Kerr/CFT correspondence.