Generalised global symmetries in holography: magnetohydrodynamic waves in a strongly interacting plasma
Abstract
We begin the exploration of holographic duals to theories with generalised global (higherform) symmetries. In particular, we focus on the case of magnetohydrodynamics (MHD) in strongly coupled plasmas by constructing and analysing a holographic dual to a recent, generalised global symmetrybased formulation of dissipative MHD. The simplest holographic dual to the effective theory of MHD that was proposed as a description of plasmas with any equation of state and transport coefficients contains dynamical graviton and twoform gauge field fluctuations in a magnetised black brane background. The dual field theory, which is closely related to the large$N_c$, $\mathcal{N} = 4$ supersymmetric YangMills theory at (infinitely) strong coupling, is, as we argue, in our setup coupled to a dynamical $U(1)$ gauge field with a renormalisation conditiondependent electromagnetic coupling. After constructing the holographic dictionary for gaugegravity duals of field theories with higherform symmetries, we compute the dual equation of state and transport coefficients, and for the first time analyse phenomenology of MHD waves in a strongly interacting, dense plasma with a (holographic) microscopic description. From weak to extremely strong magnetic fields, several predictions for the behaviour of Alfvén and magnetosonic waves are discussed.
 Publication:

arXiv eprints
 Pub Date:
 July 2017
 arXiv:
 arXiv:1707.04182
 Bibcode:
 2017arXiv170704182G
 Keywords:

 High Energy Physics  Theory;
 Condensed Matter  Strongly Correlated Electrons;
 Nuclear Theory;
 Physics  Plasma Physics
 EPrint:
 V3: 53 pages, 13 figures, 2 tables. Comments and references added. Version published in JHEP