Transport Coefficients at Zero Temperature from Extremal Black Holes

Understand

Using the AdS/CFT correspondence we study transport coefficients of a strongly-coupled (2 +1)-dimensional field theory at {\it zero} temperature and finite charge density.

• The field theory under consideration is dual to the extremal Reissner-Nordstrom AdS_4 black hole in the bulk.
• We show that, like the cases of scalar and spinor operators studied in \cite{Faulkner:2009wj}, the correlators of charge (vector) current and energy-momentum (tensor) operators exhibit scaling behavior at low frequency.
• The existence of such low frequency behavior is related to the fact that the near-horizon geometry of the extremal black hole background has an AdS_2 factor.