Imperial College London
Alternate

Professor Andrew H Jaffe

Faculty of Natural Sciences, Department of Physics

Professor of Astrophysics and Cosmology
 
 
 
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Contact

 

+44 (0)20 7594 7526a.jaffe Website

 
 
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Assistant

 

Miss Louise Hayward +44 (0)20 7594 7679

 
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Location

 

1018BBlackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Heavens:2013:mnrasl/slt045,
author = {Heavens, A and Alsing, J and Jaffe, AH},
doi = {mnrasl/slt045},
journal = {Monthly Notices of the Royal Astronomical Society: Letters},
pages = {L6--L10},
title = {Combining size and shape in weak lensing},
url = {http://dx.doi.org/10.1093/mnrasl/slt045},
volume = {433},
year = {2013}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Weak lensing alters the size of images with a similar magnitude to the distortion due to shear. Galaxy size probes the convergence field and shapes the shear field, both of which contain cosmological information. We show the gains expected in the dark energy figure of merit if galaxy size information is used in combination with galaxy shape. In any normal analysis of cosmic shear, galaxy sizes are also studied, so this is extra statistical information that comes for free and is currently unused. There are two main results in this Letter: first, we show that size measurement can be made uncorrelated with ellipticity measurement, thus allowing the full statistical gain from the combination, provided that √area is used as a size indicator; secondly, as a proof of concept, we show that when the relevant modes are noise dominated, as is the norm for lensing surveys, the gains are substantial, with improvements of about 68 per cent in the figure of merit expected when systematic errors are ignored. An approximate treatment of such systematics such as intrinsic alignments and size–magnitude correlations, respectively, suggests that a much better improvement in the dark energy figure of merit of even a factor of ∼4 may be achieved.
AU  - Heavens,A
AU  - Alsing,J
AU  - Jaffe,AH
DO  - mnrasl/slt045
EP  - 10
PY  - 2013///
SN  - 1745-3933
SP  - 6
TI  - Combining size and shape in weak lensing
T2  - Monthly Notices of the Royal Astronomical Society: Letters
UR  - http://dx.doi.org/10.1093/mnrasl/slt045
UR  - http://hdl.handle.net/10044/1/54546
VL  - 433
ER  -
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