Results 21 to 30 of about 33,635 (203)
Proceedings of the International Astronomical Union, 2004 Cosmic shear surveys are now collecting photometric redshifts of the sources. We analyse how such photometric redshifts can be used to perform a genuine 3D analysis of the shear fields, with enhanced statistical power over conventional shear analysis on the sky.
Alan F. Heavens, Thomas D. Kitching
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Cosmic shear: Inference from forward models [PDF]
Physical Review D, 2019 Density-estimation likelihood-free inference (DELFI) has recently been proposed as an efficient method for simulation-based cosmological parameter inference. Compared to the standard likelihood-based Markov Chain Monte Carlo (MCMC) approach, DELFI has several advantages: it is highly parallelizable, there is no need to assume a possibly incorrect ...
Peter L. Taylor +5 more
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Proceedings of Baryons in Dark Matter Halos — PoS(BDMH2004), 2004 Distant galaxies are continuously deflected while travelling through the gravitational potential of the large-scale matter distribution in the Universe. The resulting distortion of the galaxy shapes can be measured statistically. Such a Cosmic Shear analysis provides a powerful tool to probe the growth of structure on different scales, and thus to ...
Tim Schrabback +3 more
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Testing modified gravity with cosmic shear [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 13 pages, 7 figures, 2 ...
Harnois-Déraps, J. +6 more
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HIERARCHICAL PROBABILISTIC INFERENCE OF COSMIC SHEAR [PDF]
The Astrophysical Journal, 2015 Point estimators for the shearing of galaxy images induced by gravitational lensing involve a complex inverse problem in the presence of noise, pixelization, and model uncertainties. We present a probabilistic forward modeling approach to gravitational lensing inference that has the potential to mitigate the biased inferences in most common point ...
Michael D. Schneider +6 more
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Sheer shear: weak lensing with one mode
The Open Journal of Astrophysics, 2019 3D data compression techniques can be used to determine the natural basis of radial eigenmodes that encode the maximum amount of information in a tomographic large-scale structure survey.
Emilio Bellini +3 more
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An Unbiased Method of Measuring the Ratio of Two Data Sets
The Astrophysical Journal Supplement Series, 2023 In certain cases of astronomical data analysis, the meaningful physical quantity to extract is the ratio R between two data sets. Examples include the lensing ratio, the interloper rate in spectroscopic redshift samples, and the decay rate of ...
Zeyang Sun +7 more
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Enhancing the cosmic shear power spectrum [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 Applying a transformation to a non-Gaussian field can enhance the information content of the resulting power spectrum, by reducing the correlations between Fourier modes. In the context of weak gravitational lensing, it has been shown that this gain in information content is significantly compromised by the presence of shape noise. We apply clipping to
Simpson, Fergus +5 more
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Shear and magnification: cosmic complementarity [PDF]
Monthly Notices of the Royal Astronomical Society, 2010 8 pages, submitted to ...
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COSMIC SHEAR MEASUREMENT USING AUTO-CONVOLVED IMAGES [PDF]
The Astrophysical Journal, 2016 ABSTRACT We study the possibility of using quadrupole moments of auto-convolved galaxy images to measure cosmic shear. The autoconvolution of an image corresponds to the inverse Fourier transformation of its power spectrum. The new method has the following advantages: the smearing effect due to the point-spread function (PSF) can be ...
Li, Xiangchong, Zhang, Jun
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