Abstract |
Generalised global symmetries are a generic feature of theories with topologically conserved
charges. For certain physical theories, these allow for an entirely symmetry based
reformulation of the low-energy physics in the hydrodynamic regime without making reference
to the specific microscopics. In this talk, we will introduce some of these ideas in the concrete
setting of magnetohydrodynamics (MHD), seen as a fluid with conserved "strings" (magnetic
field lines). We will argue that MHD is described by a novel theory of superfluidity with a
partially broken one-form symmetry. Time permitting, we will also comment on another
application of generalised global symmetries to the theory of viscoelasticity. The talk is based
on [1808.01939, 1811.04913, 1908.01175]. |