2020/11/30 by Alex Buchel
Physics and Astronomy · #Black Holes and Theoretical Physics #Black brane #Brane cosmology #Conformal map #Conformal symmetry #Cosmology and Gravitation Theories #Holography #Order (exchange) #Quantum Chromodynamics and Particle Interactions #Quasinormal mode #Spectrum (functional analysis) #Viscosity #hep-th
paper · pdf · doi:10.1103/physrevd.103.026008
published as Phys. Rev. D 103, 026008 (2021) · 34 pages, 13 figures; v2: PRD version
openalex created_date 2020/12/07 · arxiv created 2020/12/24 · openalex publication_date 2021/01/11 · arxiv updated 2021/01/20 · openalex updated_date 2026/08/05
We use holographic correspondence to study transport of the conformal plasma in ℝ2,1 in a phase with a spontaneously broken global ℤ2 symmetry. The dual black branes in a Poincare patch of asymptotically AdS4 have ``hair''---a condensate of the order parameter for the broken symmetry. This hair affects both the hydrodynamic and the nonhydrodynamic quasinormal modes of the black branes. Nonetheless, the shear viscosity of the conformal order is universal, the bulk viscosity vanishes and the speed of the sound waves is cs2=(1)/(2). We compute the low-lying spectrum of the nonhydrodynamic modes. We identify a quasinormal mode associated with the fluctuations of the ℤ2 order parameter with the positive imaginary part. The presence of this mode in the spectrum renders the holographic conformal order perturbatively unstable. Correspondingly, the dual black branes violate the correlated stability conjecture.