Title: Constraints on patchy reionization from Planck CMB temperature trispectrum

Abstract

Here, we present constraints on the patchy reionization by measuring the trispectrum of the Planck 2015 cosmic microwave background (CMB) temperature anisotropies. The patchy reionization leads to anisotropies in the CMB optical depth, and the statistics of the observed CMB anisotropies is altered. Here, we estimate the trispectrum of the CMB temperature anisotropies to constrain spatial variation of the optical depth. We show that the measured trispectrum is consistent with that from the standard lensed CMB simulation at 2σ. While no evidence of the patchy reionization is found in the Planck 2015 temperature trispectrum, the CMB constraint on the patchy reionization is significantly improved from previous works. Assuming the analytic bubble-halo model of Wang and Hu (2006), the constraint obtained in this work rules out the typical bubble size at the ionization fraction of ~ 0.5 as R ≳ 10 Mpc. Further, our constraint implies that large-scale B -modes from the patchy reionization are not a significant contamination in detecting the primordial gravitational waves of r ≳ 0.001 if the B mode induced by the patchy reionization is described by Dvorkin et al. (2009). The CMB trispectrum data starts to provide meaningful constraints on the patchy reionization.

Authors:

Namikawa, Toshiya ^[1]

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+ Show Author Affiliations

1. Stanford Univ., CA (United States). Dept. of Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology

Publication Date:

Mon Mar 05 00:00:00 EST 2018

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1437352

Alternate Identifier(s):

OSTI ID: 1423716

Grant/Contract Number:  

AC02-76SF00515; AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review. D.

Additional Journal Information:

Journal Volume: 97; Journal Issue: 6; Journal ID: ISSN 2470-0010

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS