  Gauge symmetries play an essential role in determining the interactions of
particle physics. Where do they come from? Might the gauge symmetries of the
Standard Model unify in the ultraviolet or might they be emergent in the
infrared, below some large scale close to the Planck scale? Emergent gauge
symmetries are important in quantum many-body systems in quantum phases
associated with long range entanglement and topological order, e.g., they arise
in high temperature superconductors, with string-net condensation and in the
A-phase of superfluid He-3. String-nets and superfluid He-3 exhibit emergent
properties similar to the building blocks of particle physics. Emergent gauge
symmetries also play an important role in simulations of quantum field
theories. This article discusses recent thinking on possible emergent gauge
symmetries in particle physics, commenting also on Higgs phenomena and the
vacuum energy or cosmological constant puzzle in emergent gauge systems.
