Tensor Gauge Theories of Fractons
Fractons are an exotic new class of emergent quasiparticles with severely restricted mobility, first encountered in the context of exactly solvable spin models. In this talk, I will show how the fracton phenomenon arises as a natural feature of tensor gauge theories, which provide a general framework for studying most of the known fracton phases. In particular, symmetric tensor gauge theories exhibit higher moment charge conservation laws, such as conservation of dipole moment, which can force the charges to be immobile fracton excitations. More generally, these gauge theories also feature subdimensional particle excitations which are immobile in certain directions while remaining free to move in others. I will describe how the tensor gauge theory perspective draws deep connections between fractons and other areas of physics, such as elasticity theory and gravity. Finally, I will show how the fracton phenomenon can be extended from point particles to immobile line-like excitations.