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arXiv · 1809.03924

Weak lensing distortions beyond shear

Pierre Fleury·Julien Larena·Jean-Philippe Uzan
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Abstract

When a luminous source is extended, its distortions by weak gravitational lensing are richer than a mere combination of magnification and shear. In a recent work, we proposed an elegant formalism based on complex analysis to describe and calculate such distortions. The present article further elaborates this finite-beam approach, and applies it to a realistic cosmological model. In particular, the cosmic correlations of image distortions beyond shear are predicted for the first time. These constitute new weak-lensing observables, sensitive to very-small-scale features of the distribution of matter in the Universe. While the major part of the analysis is performed in the approximation of circular sources, a general method for extending it to noncircular sources is presented and applied to the astrophysically relevant case of elliptic sources.

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Pierre Fleury, Julien Larena, Jean-Philippe Uzan. 2018-09-11. Weak lensing distortions beyond shear. https://doi.org/10.1103/physrevd.99.023526

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