TY  - JOUR
AU  - Nadal-Gisbert, S.
AU  - Navarro-Salas, J.
AU  - Pla, S.
PY  - 2023
DA  - 2023//
TI  - Low-energy states and CPT invariance at the big bang
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 085018
EP  - 16pp
VL  - 107
IS  - 8
PB  - Amer Physical Soc
AB  - 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.
SN  - 2470-0010
UR  - https://arxiv.org/abs/2302.08812
UR  - https://doi.org/10.1103/PhysRevD.107.085018
DO  - 10.1103/PhysRevD.107.085018
LA  - English
N1  - WOS:000981997800003
ID  - Nadal-Gisbert_etal2023
ER  -