Cosmological particle production in emergent rainbow spacetimes

Abstract

We investigate cosmological particle production in spacetimes where Lorentz invariance emerges in the infrared limit, but is explicitly broken in the ultraviolet regime. Our specific model focuses on the boost subgroup that supports CPT invariance and results in a momentum-dependent dispersion relation. Motivated by previous studies on spacetimes emerging from a microscopic substrate, we show how these modifications naturally lead to momentum-dependent rainbow metrics. Firstly, we investigate the possibility of reproducing cosmological particle production in spacetimes emerging from real Bose gases. We have studied the influence of non-perturbative ultraviolet corrections in time-dependent analogue spacetimes, leading to momentum-dependent emergent rainbow spacetimes. Within certain limits the analogy is sufficiently good to simulate relativistic quantum field theory in time-dependent classical backgrounds, and the quantum effects are approximately robust against the model-dependent modifications. Secondly, we analyze how significantly the particle production process deviates from the common picture. While very low-energy modes do not see the difference at all, some modes "re-enter the Hubble horizon" during the inflationary epoch, and extreme ultraviolet modes are completely insensitive to the expansion.

References in corpus (8)

• The Hubble series: Convergence properties and redshift variables
• Quantum simulation of cosmic inflation in two-component Bose-Einstein condensates
• "Cosmological" quasiparticle production in harmonically trapped superfluid gases
• Analogue model of a FRW universe in Bose-Einstein condensates: Application of the classical field method
• Observer dependence for the phonon content of the sound field living on the effective curved space-time background of a Bose-Einstein condensate
• Trans-Planckian physics and signature change events in Bose gas hydrodynamics
• Cosmography: Extracting the Hubble series from the supernova data
• Massive phonon modes from a BEC-based analog model

Cited by in corpus (5)

• Lorentz symmetry breaking as a quantum field theory regulator
• Bounding the greybody factors for Schwarzschild black holes
• Gravitational dynamics in Bose Einstein condensates
• Analogue Models for Emergent Gravity
• Emergent gravity: the BEC paradigm