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arXiv · 2302.08812

Low Energy States and CPT invariance at the Big Bang

Sergi Nadal-Gisbert·José Navarro-Salas·Silvia Pla
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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.

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Sergi Nadal-Gisbert, José Navarro-Salas, Silvia Pla. 2023-02-17. Low Energy States and CPT invariance at the Big Bang. https://doi.org/10.1103/physrevd.107.085018

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