Small black holes in the large D limit

Understand

The large D limit of AdS_2 X S^{D-2} solutions in the particular higher-derivative Lovelock-type theory is analyzed.

• The theory and the solutions were originally considered in an attempt to effectively describe near-horizon behavior of D-dimensional spherically symmetric 2-charge small extremal black holes which in superstring theory context are assumed to correspond to configurations in S^1 \times T^{9-D} compactification schemes in which fundamental string is wound around circle S^1.
• Though in D -> \infty limit the action contains infinite number of higher-derivative terms, their contributions to equations of motion sum into simple exponential form which allows us to find explicit solutions.
• A simplicity of this example gives us the opportunity to study some connections between \alpha' and 1/D expansions.