Conformal field theories at nonzero temperature: Operator product expansions, Monte Carlo, and holography

We compute the nonzero temperature conductivity of conserved flavor currents in conformal field theories (CFTs) in 2+1 space-time dimensions. At frequencies much greater than the temperature, ℏω≫kBT, the ω dependence can be computed from the operator product expansion (OPE) between the currents and operators, which acquire a nonzero expectation value at T>0. Such results are found to be in excellent agreement with quantum Monte Carlo studies of …