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Full-Text Articles in Astrophysics and Astronomy

Discovering New Strong Gravitational Lenses In The Desi Legacy Imaging Surveys, Xiaosheng Huang, Christopher Storfer, A. Gu, V. Ravi, A. Pilon, W. Sheu, R. Venguswamy, S. Bankda, A. Dey, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, R. Sajith, E. F. Schlafly, D. J. Schlegel May 2020

Discovering New Strong Gravitational Lenses In The Desi Legacy Imaging Surveys, Xiaosheng Huang, Christopher Storfer, A. Gu, V. Ravi, A. Pilon, W. Sheu, R. Venguswamy, S. Bankda, A. Dey, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, R. Sajith, E. F. Schlafly, D. J. Schlegel

Physics and Astronomy

We have conducted a search for new strong gravitational lensing systems in the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys’ Data Release 8. We use deep residual neural networks, building on previous work presented in Huang et al. (2020). These surveys together cover approximately one third of the sky visible from the northern hemisphere, reaching a z-band AB magnitude of ∼ 22.5. We compile a training sample that consists of known lensing systems as well as non-lenses in the Legacy Surveys and the Dark Energy Survey. After applying our trained neural networks to the survey data, we visually inspect and …


Significance Of Gravitational Nonlinearities On The Dynamics Of Disk Galaxies, Alexandre Deur, Corey Sargent, Balša Terzić Jan 2020

Significance Of Gravitational Nonlinearities On The Dynamics Of Disk Galaxies, Alexandre Deur, Corey Sargent, Balša Terzić

Physics Faculty Publications

The discrepancy between the visible mass in galaxies or galaxy clusters and that inferred from their dynamics is well known. The prevailing solution to this problem is dark matter. Here we show that a different approach, one that conforms to both the current standard model of particle physics and general relativity (GR), explains the recently observed tight correlation between the galactic baryonic mass and the measured accelerations in the galaxy. Using direct calculations based on GR's Lagrangian and parameter-free galactic models, we show that the nonlinear effects of GR make baryonic matter alone sufficient to explain this observation. Our approach …