A semiclassical singularity theorem

TY - JOUR

T1 - A semiclassical singularity theorem

AU - Fewster, Chris

AU - Kontou, Eleni

N1 - © 2022 The Author(s)

PY - 2022/3/18

Y1 - 2022/3/18

N2 - Quantum fields do not satisfy the pointwise energy conditions that are assumed in the original singularity theorems of Penrose and Hawking. Accordingly, semiclassical quantum gravity lies outside their scope. Although a number of singularity theorems have been derived under weakened energy conditions, none is directly derived from quantum field theory. Here, we employ a quantum energy inequality satisfied by the quantized minimally coupled linear scalar field to derive a singularity theorem valid in semiclassical gravity. By considering a toy cosmological model, we show that our result predicts timelike geodesic incompleteness on plausible timescales with reasonable conditions at a spacelike Cauchy surface.

AB - Quantum fields do not satisfy the pointwise energy conditions that are assumed in the original singularity theorems of Penrose and Hawking. Accordingly, semiclassical quantum gravity lies outside their scope. Although a number of singularity theorems have been derived under weakened energy conditions, none is directly derived from quantum field theory. Here, we employ a quantum energy inequality satisfied by the quantized minimally coupled linear scalar field to derive a singularity theorem valid in semiclassical gravity. By considering a toy cosmological model, we show that our result predicts timelike geodesic incompleteness on plausible timescales with reasonable conditions at a spacelike Cauchy surface.

UR - https://arxiv.org/abs/2108.12668

U2 - 10.1088/1361-6382/ac566b

DO - 10.1088/1361-6382/ac566b

M3 - Article

SN - 0264-9381

VL - 39

JO - Classical and Quantum Gravity

JF - Classical and Quantum Gravity

IS - 7

M1 - 075028

ER -