Superfluid analogies of cosmological phenomena

TL;DR

This paper explores how superfluid 3He-A models various cosmological phenomena, illustrating the emergence of fundamental particles, gauge fields, and gravity, and providing insights into quantum field theory and vacuum energy.

Contribution

It demonstrates that superfluid 3He-A serves as a laboratory model for cosmological phenomena, linking condensed matter physics with high-energy physics and quantum field theory.

Findings

Superfluid 3He-A models chiral and gauge phenomena observed in cosmology.

Vacuum energy in superfluid 3He-A can be nullified beyond effective theory.

Experimental evidence supports anomalous fermionic charge nucleation.

Abstract

Superfluid 3He-A gives example of how chirality, Weyl fermions, gauge fields and gravity appear in low energy corner together with corresponding symmetries, including Lorentz symmetry and local SU(N). This supports idea that quantum field theory (Standard Model or GUT) is effective theory describing low-energy phenomena. * Momentum space topology of fermionic vacuum provides topological stability of universality class of systems, where above properties appear. * BCS scheme for 3He-A incorporates both ``relativistic'' infrared regime and ultraviolet ``transplanckian'' range: subtle issues of cut-off in quantum field theory and anomalies can be resolved on physical grounds. This allows to separate ``renormalizable'' terms in action, treated by effective theory, from those obtained only in ``transPlanckian'' physics. * Energy density of superfluid vacuum within effective theory is ~ E_{Planck}^4. Stability analysis of ground state beyond effective theory leads to exact nullification of vacuum energy: equilibrium vacuum is not gravitating. In nonequilibrium, vacuum energy is of order energy density of matter. * 3He-A provides experimental prove for anomalous nucleation of fermionic charge according to Adler-Bell-Jackiw. * Helical instability in 3He-A is described by the same equations as formation of magnetic field by right electrons in Joyce-Shaposhnikov scenario. * Macroscopic parity violating effect and angular momentum paradox are both desribed by axial gravitational Chern-Simons action. * High energy dispersion of quasiparticle spectrum allow to treat problems of vacuum in presence of event horizon, etc.