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{Mootoovaloo:2020:mnras/staa2102,
author = {Mootoovaloo, A and Heavens, AF and Jaffe, AH and Leclercq, F},
doi = {mnras/staa2102},
journal = {Monthly Notices of the Royal Astronomical Society},
pages = {2213--2226},
title = {Parameter Inference for Weak Lensing using Gaussian Processes and MOPED},
url = {http://dx.doi.org/10.1093/mnras/staa2102},
volume = {497},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - In this paper, we propose a Gaussian Process (GP) emulator for the calculation both of tomographic weak lensing band powers, and of coefficients of summary data massively compressed with the MOPED algorithm. In the former case cosmological parameter inference is accelerated by a factor of ∼10–30 compared with Boltzmann solver class applied to KiDS-450 weak lensing data. Much larger gains of order 103 will come with future data, and MOPED with GPs will be fast enough to permit the Limber approximation to be dropped, with acceleration in this case of ∼105. A potential advantage of GPs is that an error on the emulated function can be computed and this uncertainty incorporated into the likelihood. However, it is known that the GP error can be unreliable when applied to deterministic functions, and we find, using the Kullback–Leibler divergence between the emulator and class likelihoods, and from the uncertainties on the parameters, that agreement is better when the GP uncertainty is not used. In future, weak lensing surveys such as Euclid, and the Legacy Survey of Space and Time, will have up to ∼104 summary statistics, and inference will be correspondingly more challenging. However, since the speed of MOPED is determined not the number of summary data, but by the number of parameters, MOPED analysis scales almost perfectly, provided that a fast way to compute the theoretical MOPED coefficients is available. The GP provides such a fast mechanism.
AU  - Mootoovaloo,A
AU  - Heavens,AF
AU  - Jaffe,AH
AU  - Leclercq,F
DO  - mnras/staa2102
EP  - 2226
PY  - 2020///
SN  - 0035-8711
SP  - 2213
TI  - Parameter Inference for Weak Lensing using Gaussian Processes and MOPED
T2  - Monthly Notices of the Royal Astronomical Society
UR  - http://dx.doi.org/10.1093/mnras/staa2102
UR  - http://arxiv.org/abs/2005.06551v1
UR  - http://hdl.handle.net/10044/1/81411
VL  - 497
ER  -
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