Goldstone bosons at non-zero temperature

Abstract

Spontaneous symmetry breaking in quantum field theories at non-zero temperature still holds fundamental open questions, in particular what happens to vacuum Goldstone bosons when the temperature is increased. By investigating a complex scalar field theory on the lattice we demonstrate that Goldstone bosons at non-zero temperature behave like screened massless particle-like excitations, so-called thermoparticles, which continue to exist even in the symmetry-restored phase of the theory. We provide non-perturbative evidence for the functional form of the Goldstone mode's dissipative behaviour, and determine its corresponding spectral properties. Since the persistence of thermal Goldstone modes within symmetry-restored phases is predicted to be a model-independent characteristic, this has fundamental consequences for systems in which continuous symmetries are restored at high temperatures.

7 pages, 3 figures; v2: additional discussion added, matches published version. Figure data attached

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Cited by in corpus (1)

• Goldstone bosons across thermal phase transitions