Navigation auf zora.uzh.ch

Search ZORA

ZORA (Zurich Open Repository and Archive)

Sample Variance in Cosmological Observations with a Narrow Field of View

Espenshade, Peter; Yoo, Jaiyul (2023). Sample Variance in Cosmological Observations with a Narrow Field of View. The Astrophysical Journal, 953(2):163.

Abstract

Surveys with a narrow field of view can play an important role in probing cosmology, but inferences from these surveys suffer from large sample variance, arising from random fluctuations around the cosmic mean. The standard method for computing the sample variance is based on two key approximations: treating perturbations linearly and the survey geometry as a box. We demonstrate that it can lead to a significant underestimate of the sample variance in narrow surveys. We present a new method for accurately computing the sample variance and apply our method to the recent observations of the warm–hot intergalactic medium (WHIM) based on spectroscopic measurements of blazars. We find that the sample variances in these surveys are significantly larger than the quoted measurement errors; for example, the cosmic mean baryon density contained in the WHIM could be lower by 54% at 1σ fluctuation than estimated in one observation. Accurately quantifying the sample variance is essential in deriving correct interpretations of the measurements in surveys with a small field of view.

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute for Computational Science
Dewey Decimal Classification:530 Physics
Scopus Subject Areas:Physical Sciences > Astronomy and Astrophysics
Physical Sciences > Space and Planetary Science
Uncontrolled Keywords:Space and Planetary Science, Astronomy and Astrophysics
Language:English
Date:1 August 2023
Deposited On:31 Jan 2024 12:42
Last Modified:30 Oct 2024 02:41
Publisher:IOP Publishing
ISSN:1538-4357
OA Status:Gold
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.3847/1538-4357/ace71b
Download PDF  'Sample Variance in Cosmological Observations with a Narrow Field of View'.
Preview
  • Content: Published Version
  • Language: English
  • Licence: Creative Commons: Attribution 4.0 International (CC BY 4.0)

Metadata Export

Statistics

Citations

Altmetrics

Downloads

1 download since deposited on 31 Jan 2024
1 download since 12 months
Detailed statistics

Authors, Affiliations, Collaborations

Similar Publications