Nearly Critical Superfluids in Keldysh-Schwinger Formalism

Abstract

We examine the effective theory of critical dynamics near superfluid phase transitions in the framework of the Keldysh-Schwinger formalism. We focus on the sector capturing the dynamics of the complex order parameter and the conserved current corresponding to the broken global symmetry. After constructing the theory up to quadratic order in the $a$-fields, we compare the resulting stochastic system with Model F as well as with holography. We highlight the role of a time independent gauge symmetry of the effective theory also known as ``chemical shift". Finally, we consider the limiting behaviour at energies much lower than the gap of the amplitude mode by integrating out the high energy degrees of freedom to reproduce the effective theory of superfluids.

arXiv comment23 pages

References in corpus (9)

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• Theory of diffusive fluctuations
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Cited by in corpus (6)

• Holographic Schwinger-Keldysh effective field theories including a non-hydrodynamic mode
• Universality of pseudo-Goldstone damping near critical points
• Simple holographic dual of the Maxwell-Cattaneo model & the fate of KMS symmetry for non-hydrodynamic modes
• Effective Description of Ajar Systems with a $U(1)$ Symmetry
• Critical and near-critical relaxation of holographic superfluids
• Chiral phase transition: effective field theory and holography