Imperial College London
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ProfessorAlanHeavens

Faculty of Natural Sciences, Department of Physics

Chair in Astrostatistics
 
 
 
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Contact

 

+44 (0)20 7594 2930a.heavens Website

 
 
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Location

 

1018EBlackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Leclercq:2021:mnrasl/slab081,
author = {Leclercq, F and Heavens, A},
doi = {mnrasl/slab081},
journal = {Monthly Notices of the Royal Astronomical Society},
pages = {L85--L90},
title = {On the accuracy and precision of correlation functions and field-levelinference in cosmology},
url = {http://dx.doi.org/10.1093/mnrasl/slab081},
volume = {506},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We present a comparative study of the accuracy and precision of correlation function methods and full-field inference in cosmological data analysis. To do so, we examine a Bayesian hierarchical model that predicts lognormal (LN) fields and their two-point correlation function. Although a simplified analytic model, the LN model produces fields that share many of the essential characteristics of the present-day non-Gaussian cosmological density fields. We use three different statistical techniques: (i) a standard likelihood-based analysis of the two-point correlation function; (ii) a likelihood-free (simulation-based) analysis of the two-point correlation function; (iii) a field-level analysis, made possible by the more sophisticated data assimilation technique. We find that (a) standard assumptions made to write down a likelihood for correlation functions can cause significant biases, a problem that is alleviated with simulation-based inference; and (b) analysing the entire field offers considerable advantages over correlation functions, through higher accuracy, higher precision, or both. The gains depend on the degree of non-Gaussianity, but in all cases, including for weak non-Gaussianity, the advantage of analysing the full field is substantial.
AU  - Leclercq,F
AU  - Heavens,A
DO  - mnrasl/slab081
EP  - 90
PY  - 2021///
SN  - 0035-8711
SP  - 85
TI  - On the accuracy and precision of correlation functions and field-levelinference in cosmology
T2  - Monthly Notices of the Royal Astronomical Society
UR  - http://dx.doi.org/10.1093/mnrasl/slab081
UR  - http://arxiv.org/abs/2103.04158v1
UR  - http://hdl.handle.net/10044/1/93555
VL  - 506
ER  -
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