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Title: The variance of the locally measured Hubble parameter explained with different estimators

Abstract

We study the expected variance of measurements of the Hubble constant, H {sub 0}, as calculated in either linear perturbation theory or using non-linear velocity power spectra derived from N -body simulations. We compare the variance with that obtained by carrying out mock observations in the N-body simulations, and show that the estimator typically used for the local Hubble constant in studies based on perturbation theory is different from the one used in studies based on N-body simulations. The latter gives larger weight to distant sources, which explains why studies based on N-body simulations tend to obtain a smaller variance than that found from studies based on the power spectrum. Although both approaches result in a variance too small to explain the discrepancy between the value of H {sub 0} from CMB measurements and the value measured in the local universe, these considerations are important in light of the percent determination of the Hubble constant in the local universe.

Authors:
; ;  [1]
  1. Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)
Publication Date:
OSTI Identifier:
22679976
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DISTURBANCES; NONLINEAR PROBLEMS; PERTURBATION THEORY; RELICT RADIATION; SPECTRA; UNIVERSE; VELOCITY; VISIBLE RADIATION

Citation Formats

Odderskov, Io, Hannestad, Steen, and Brandbyge, Jacob, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: jacobb@phys.au.dk. The variance of the locally measured Hubble parameter explained with different estimators. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/03/022.
Odderskov, Io, Hannestad, Steen, & Brandbyge, Jacob, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: jacobb@phys.au.dk. The variance of the locally measured Hubble parameter explained with different estimators. United States. doi:10.1088/1475-7516/2017/03/022.
Odderskov, Io, Hannestad, Steen, and Brandbyge, Jacob, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: jacobb@phys.au.dk. Wed . "The variance of the locally measured Hubble parameter explained with different estimators". United States. doi:10.1088/1475-7516/2017/03/022.
@article{osti_22679976,
title = {The variance of the locally measured Hubble parameter explained with different estimators},
author = {Odderskov, Io and Hannestad, Steen and Brandbyge, Jacob, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: jacobb@phys.au.dk},
abstractNote = {We study the expected variance of measurements of the Hubble constant, H {sub 0}, as calculated in either linear perturbation theory or using non-linear velocity power spectra derived from N -body simulations. We compare the variance with that obtained by carrying out mock observations in the N-body simulations, and show that the estimator typically used for the local Hubble constant in studies based on perturbation theory is different from the one used in studies based on N-body simulations. The latter gives larger weight to distant sources, which explains why studies based on N-body simulations tend to obtain a smaller variance than that found from studies based on the power spectrum. Although both approaches result in a variance too small to explain the discrepancy between the value of H {sub 0} from CMB measurements and the value measured in the local universe, these considerations are important in light of the percent determination of the Hubble constant in the local universe.},
doi = {10.1088/1475-7516/2017/03/022},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 03,
volume = 2017,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}