Propagators for gauge-invariant observables in cosmology

Markus B. Fröb; William C. C. Lima

doi:10.1088/1361-6382/aab427

Propagators for gauge-invariant observables in cosmology

Markus B. Fröb, William C. C. Lima

Mathematics

Research output: Contribution to journal › Article › peer-review

Abstract

We make a proposal for gauge-invariant observables in perturbative quantum gravity in cosmological spacetimes, building on the recent work of Brunetti et al. [JHEP 08 (2016) 032]. These observables are relational, and are obtained by evaluating the field operator in a field-dependent coordinate system. We show that it is possible to define this coordinate system such that the non-localities inherent in any higher-order observable in quantum gravity are causal, i.e., the value of the gauge-invariant observable at a point x only depends on the metric and inflation perturbations in the past light cone of x. We then construct propagators for the metric and inflaton perturbations in a gauge adapted to that coordinate system, which simplifies the calculation of loop corrections, and give explicit expressions for relevant cases: matter- and radiation-dominated eras and slow-roll inflation.

Original language	English
Number of pages	34
Journal	Classical and Quantum Gravity
Volume	35
Issue number	9
DOIs	https://doi.org/10.1088/1361-6382/aab427 https://doi.org/10.1088/1361-6382/aab427
Publication status	Published - 23 Mar 2018

Bibliographical note

© 2018 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

Access to Document

10.1088/1361-6382/aab427Licence: Other
10.1088/1361-6382/aab427Licence: Unspecified

Fröb+et+al_2018_Class._Quantum_Grav._10.1088_1361-6382_aab427
© 2018 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details
Accepted author manuscript, 710 KBLicence: Other

Cite this

@article{c852117fd44c447f9a0e4f7a2b4f487f,

title = "Propagators for gauge-invariant observables in cosmology",

abstract = "We make a proposal for gauge-invariant observables in perturbative quantum gravity in cosmological spacetimes, building on the recent work of Brunetti et al. [JHEP 08 (2016) 032]. These observables are relational, and are obtained by evaluating the field operator in a field-dependent coordinate system. We show that it is possible to define this coordinate system such that the non-localities inherent in any higher-order observable in quantum gravity are causal, i.e., the value of the gauge-invariant observable at a point x only depends on the metric and inflation perturbations in the past light cone of x. We then construct propagators for the metric and inflaton perturbations in a gauge adapted to that coordinate system, which simplifies the calculation of loop corrections, and give explicit expressions for relevant cases: matter- and radiation-dominated eras and slow-roll inflation.",

author = "Fr{\"o}b, {Markus B.} and Lima, {William C. C.}",

note = "{\textcopyright} 2018 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher{\textquoteright}s self-archiving policy. Further copying may not be permitted; contact the publisher for details",

year = "2018",

month = mar,

day = "23",

doi = "10.1088/1361-6382/aab427",

language = "English",

volume = "35",

journal = "Classical and Quantum Gravity",

issn = "0264-9381",

publisher = "IOP Publishing",

number = "9",

}

TY - JOUR

T1 - Propagators for gauge-invariant observables in cosmology

AU - Fröb, Markus B.

AU - Lima, William C. C.

N1 - © 2018 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2018/3/23

Y1 - 2018/3/23

N2 - We make a proposal for gauge-invariant observables in perturbative quantum gravity in cosmological spacetimes, building on the recent work of Brunetti et al. [JHEP 08 (2016) 032]. These observables are relational, and are obtained by evaluating the field operator in a field-dependent coordinate system. We show that it is possible to define this coordinate system such that the non-localities inherent in any higher-order observable in quantum gravity are causal, i.e., the value of the gauge-invariant observable at a point x only depends on the metric and inflation perturbations in the past light cone of x. We then construct propagators for the metric and inflaton perturbations in a gauge adapted to that coordinate system, which simplifies the calculation of loop corrections, and give explicit expressions for relevant cases: matter- and radiation-dominated eras and slow-roll inflation.

AB - We make a proposal for gauge-invariant observables in perturbative quantum gravity in cosmological spacetimes, building on the recent work of Brunetti et al. [JHEP 08 (2016) 032]. These observables are relational, and are obtained by evaluating the field operator in a field-dependent coordinate system. We show that it is possible to define this coordinate system such that the non-localities inherent in any higher-order observable in quantum gravity are causal, i.e., the value of the gauge-invariant observable at a point x only depends on the metric and inflation perturbations in the past light cone of x. We then construct propagators for the metric and inflaton perturbations in a gauge adapted to that coordinate system, which simplifies the calculation of loop corrections, and give explicit expressions for relevant cases: matter- and radiation-dominated eras and slow-roll inflation.

U2 - 10.1088/1361-6382/aab427

DO - 10.1088/1361-6382/aab427

M3 - Article

VL - 35

JO - Classical and Quantum Gravity

JF - Classical and Quantum Gravity

SN - 0264-9381

IS - 9

ER -