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arXiv · 2510.19798

Detecting gravitational lensing by matter currents

C. Murray·R. Kou·J. G. Bartlett
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Abstract

We explore the observational prospects for detecting gravitational lensing induced by cosmological matter currents, a relativistic correction to the standard density lensing effect arising from the motion of matter. We propose to isolate this contribution by cross-correlating the weak-lensing convergence field with a reconstructed cosmic momentum field inferred from galaxy redshift surveys. Using numerical simulations, we demonstrate that this reconstructed momentum field is uncorrelated with the density lensing signal, enabling a clean separation of the gravitomagnetic component. We then forecast the detectability of this signal for upcoming wide-field galaxy and weak-lensing surveys, showing that a statistically significant detection may be achievable under realistic observational conditions. Such a measurement would provide the first direct probe of the large-scale cosmic momentum field, offering a novel test of general relativity and Lorentz invariance on cosmological scales.

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C. Murray, R. Kou, J. G. Bartlett. 2025-10-22. Detecting gravitational lensing by matter currents. https://doi.org/10.1051/0004-6361/202557794

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