%0 Journal Article
%T Low-energy states and CPT invariance at the big bang
%A Nadal-Gisbert, S.
%A Navarro-Salas, J.
%A Pla, S.
%J Physical Review D
%D 2023
%V 107
%N 8
%I Amer Physical Soc
%@ 2470-0010
%G English
%F Nadal-Gisbert_etal2023
%O WOS:000981997800003
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5585), last updated on Wed, 02 Aug 2023 07:21:50 +0000
%X 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 -12 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.
%R 10.1103/PhysRevD.107.085018
%U https://arxiv.org/abs/2302.08812
%U https://doi.org/10.1103/PhysRevD.107.085018
%P 085018-16pp