2016/12/31 by Subham Dutta Chowdhury, Justin R. David, Shiroman Prakash
Physics and Astronomy · #Black Holes and Theoretical Physics #Cauchy stress tensor #Causality (physics) #Conformal field theory #Conformal map #Constant (computer programming) #Function (biology) #High-Energy Particle Collisions Research #Operator product expansion #Quantum Chromodynamics and Particle Interactions #Sum rule in quantum mechanics #Tensor (intrinsic definition) #hep-th
paper · pdf · doi:10.1007/jhep07(2017)119
published as JHEP 07 (2017) 119 · Corrected typos, JHEP version
openalex created_date 2016/12/16 · openalex publication_date 2017/07/01 · arxiv created 2017/07/26 · arxiv updated 2017/12/12 · openalex updated_date 2026/08/05
We derive spectral sum rules in the shear channel for conformal field theories at finite temperature in general d ≥ 3 dimensions. The sum rules result from the OPE of the stress tensor at high frequency as well as the hydrodynamic behaviour of the theory at low frequencies. The sum rule states that a weighted integral of the spectral density over frequencies is proportional to the energy density of the theory. We show that the proportionality constant can be written in terms the Hofman-Maldacena variables t 2 , t 4 which determine the three point function of the stress tensor. For theories which admit a two derivative gravity dual this proportionality constant is given by (d)/(2(d+1)) . We then use causality constraints and obtain bounds on the sum rule which are valid in any conformal field theory. Finally we demonstrate that the high frequency behaviour of the spectral function in the vector and the tensor channel are also determined by the Hofman-Maldacena variables.