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- 30.04., Tomas Brauner (UiS): Topology of spontaneous symmetry breaking, emergent higher-form and higher-group symmetries
Abstract: Spontaneous breaking of a continuous global symmetry implies as a rule the existence of new, emergent symmetries, associated with the topology of the vacuum manifold. These may take the form of ordinary symmetries associated to a conserved current and localized charged excitations, or higher-form symmetries, acting on extended topological defects. I will give a brief introduction to the above-mentioned concepts, and then show how higher-form symmetries can be combined into a more general mathematical structure still, referred to as higher-group symmetry. This is a concept that has recently attracted attention in the high-energy theory community. It however turns out to be also relevant for systems as mundane as superfluid mixtures. - 14.05., Magnus Malmquist (NTNU):
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