Gauge-invariant tensor perturbations induced from baryon-CDM relative velocity and the B-mode polarization of the CMB

James Gurian, Donghui Jeong, Jai-chan Hwang, and Hyerim Noh
Phys. Rev. D 104, 083534 – Published 20 October 2021

Abstract

At second order, scalar perturbations can source traceless and transverse perturbations to the metric, called induced gravitational waves (IGWs). The apparent gauge dependence of the IGWs obscures the interpretation of the stochastic gravitational wave signal. To elucidate the gauge dependence, we study the IGWs from manifestly gauge-invariant scalar perturbations—namely, the relative velocity between baryons and cold dark matter. From this relative velocity perturbation, we compute the dimensionless gravitational wave power spectrum and the corresponding expected angular power spectrum of the B-mode polarization of the cosmic microwave background. Although the effect turns out to be unobservably small, the calculation demonstrates both the importance of using observable quantities to remove the gauge ambiguity and the observable consequences of tensor perturbations which are not propagating gravitational waves.

  • Figure
  • Figure
  • Figure
  • Received 13 April 2021
  • Accepted 16 September 2021

DOI:https://doi.org/10.1103/PhysRevD.104.083534

© 2021 American Physical Society

Physics Subject Headings (PhySH)

Gravitation, Cosmology & Astrophysics

Authors & Affiliations

James Gurian and Donghui Jeong

  • Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

Jai-chan Hwang

  • Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu 702-701, Korea and Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS), Daejeon 34051, Korea

Hyerim Noh

  • Korea Astronomy and Space Science Institute, Daejeon 305-348, Korea

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 104, Iss. 8 — 15 October 2021

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review D

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×