T-duality and high-derivative gravity theories: the BTZ black hole/string paradigm

Understand

We show that the temperature and entropy of a BTZ black hole are invariant under T-duality to next to leading order in $M_\star^{-2}$, $M_\star$ being the scale suppressing higher-curvature/derivative terms in the Lagrangian.

• We work in the framework of a two-parameter family of theories exhibiting T-duality, which includes (but goes beyond) String Theory.
• Interestingly enough, the AdS/CFT correspondence enforces quantization conditions on these parameters.
• In the particular case of bosonic/heterotic string theory, our results extend those of a classical paper by Horowitz and Welch.