Low Energy States and CPT invariance at the Big Bang

Abstract

In this paper, we analyze the quantum vacuum in a radiation-dominated and CPT-invariant universe by further imposing the quantum states to be ultraviolet regular i.e., satisfying the Hadamard/adiabatic condition. For scalar fields, this is enforced by constructing the vacuum via the States of Low Energy proposal. For spin-$\frac{1}{2}$ fields, we extend this proposal for a FLRW spacetime and apply it for the radiation-dominated and CPT-invariant universe. We focus on minimizing the smeared energy density around the Big Bang and give strong evidence that the resulting states satisfy the Hadamard/adiabatic condition. These states are then self-consistent candidates as effective Big Bang quantum vacuum from the field theory perspective.

21 pages. PRD version

References in corpus (11)

• Cosmological Particle Production: A Review
• Preferred instantaneous vacuum for linear scalar fields in cosmological space-times
• States of Low Energy on Robertson-Walker Spacetimes
• Equivalence of Adiabatic and DeWitt-Schwinger renormalization schemes
• States of Low Energy in bouncing inflationary scenarios in Loop Quantum Cosmology
• Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum
• Probing the Big Bang with quantum fields
• Note on the pragmatic mode-sum regularization method: translational-splitting in a cosmological background
• Equivalence of the adiabatic expansion and Hadamard renormalization for a charged scalar field
• Massive particle pair production and oscillation in Friedman Universe: dark energy and matter interaction
• Argument for the radiation-dominated behavior of matter fields in the preinflationary era

Cited by in corpus (2)

• States of low energy in the Schwinger effect
• States of Low Energy on Bianchi I spacetimes