Results 91 to 100 of about 786,932 (316)

Identification of Galaxy–Galaxy Strong Lens Candidates in the DECam Local Volume Exploration Survey Using Machine Learning

The Astrophysical Journal, 2023
We perform a search for galaxy–galaxy strong lens systems using a convolutional neural network (CNN) applied to imaging data from the first public data release of the DECam Local Volume Exploration Survey, which contains ∼520 million astronomical sources
E. A. Zaborowski, A. Drlica-Wagner, F. Ashmead, J. F. Wu, R. Morgan, C. R. Bom, A. J. Shajib, S. Birrer, W. Cerny, E. J. Buckley-Geer, B. Mutlu-Pakdil, P. S. Ferguson, K. Glazebrook, S. J. Gonzalez Lozano, Y. Gordon, M. Martinez, V. Manwadkar, J. O’Donnell, J. Poh, A. Riley, J. D. Sakowska, L. Santana-Silva, B. X. Santiago, D. Sluse, C. Y. Tan, E. J. Tollerud, A. Verma, J. A. Carballo-Bello, Y. Choi, D. J. James, N. Kuropatkin, C. E. Martínez-Vázquez, D. L. Nidever, J. L. Nilo Castellon, N. E. D. Noël, K. A. G. Olsen, A. B. Pace, S. Mau, B. Yanny, A. Zenteno, T. M. C. Abbott, M. Aguena, O. Alves, F. Andrade-Oliveira, S. Bocquet, D. Brooks, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, F. J. Castander, C. J. Conselice, M. Costanzi, M. E. S. Pereira, J. De Vicente, S. Desai, J. P. Dietrich, P. Doel, S. Everett, I. Ferrero, B. Flaugher, D. Friedel, J. Frieman, J. García-Bellido, D. Gruen, R. A. Gruendl, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, K. Kuehn, H. Lin, J. L. Marshall, P. Melchior, J. Mena-Fernández, F. Menanteau, R. Miquel, A. Palmese, F. Paz-Chinchón, A. Pieres, A. A. Plazas Malagón, J. Prat, M. Rodriguez-Monroy, A. K. Romer, E. Sanchez, V. Scarpine, I. Sevilla-Noarbe, M. Smith, E. Suchyta, C. To, N. Weaverdyck, DELVE & DES Collaborations   +91 more
doaj   +1 more source

Energy Symmetry Breaking of Dirac and Weyl Fermions in Magnetized Spinning Conical Geometries

Advanced Theory and Simulations, EarlyView.
Exact solutions for relativistic fermions in magnetized, spinning conical geometries reveal defect‐induced symmetry breaking between fermion and antifermion energies. Energy levels depend on the magnetic field, background geometry, and fractionalized spin. When the defect's spin dominates, quantum effects diminish.
Abdullah Guvendi, Omar Mustafa
wiley   +1 more source

Lensing Point-spread Function of Coherent Astrophysical Sources and Nontrivial Wave Effects

The Astrophysical Journal
Most research on astrophysical lensing has been conducted using the geometric optics framework, where there exists a clear concept of lensing images. However, wave optics effects can be important for coherent sources, e.g., pulsars, fast radio bursts ...
Xun Shi
doaj   +1 more source

Dark Matter as Gravitational Solitons in the Weak Field Limit

Universe, 2020
In this paper, we will describe the idea that dark matter partly consists of gravitational solitons (gravisolitons). The corresponding solution is valid for weak gravitational fields (weak field limit) with respect to a background metric.
Torsten Asselmeyer-Maluga, Jerzy Król
doaj   +1 more source

Limits on Stellar-Mass Compact Objects as Dark Matter from Gravitational Lensing of Type Ia Supernovae. [PDF]

Physical Review Letters, 2017
The nature of dark matter (DM) remains unknown despite very precise knowledge of its abundance in the Universe. An alternative to new elementary particles postulates DM as made of macroscopic compact halo objects (MACHO) such as black holes formed in the
M. Zumalacárregui, U. Seljak
semanticscholar   +1 more source

Exploring the relationship between growth in online shopping and multichannel food consumers

Applied Economic Perspectives and Policy, EarlyView.
Abstract During the pandemic, many food retailers began offering online shopping options, primarily in reaction to rising consumer demand for such options, which was a response to supply chain disruptions and fear of contagion and food scarcity.
Mackenzie Gill, Dawn Thilmany
wiley   +1 more source

Microlensing-Based Studies of the Unresolved Structure of AGNs and the Composition of Lensing Galaxies

Open Astronomy, 2011
Multiple images of quasars formed by gravitational lensing are typically seen through the lensing galaxy. The granulation of the galaxy in stars or other compact objects induces local (‘microscopic’) but strong fluctuations in the gravitational potential
Gradolph Teresa Mediavilla, Gradolph Evencio Mediavilla, Muñoz Jose Antonio   +2 more
doaj   +1 more source

Gravitational Lenses

, 1999
The purpose of these lecture notes is to describe the gravitational lens effects in different astrophysical contexts. These notes are voluntarily focused on the fundamental mechanisms and the basic concepts that are useful to describe these effects. The observational consequences are presented in more details in accompanying notes by Y. Mellier.
openaire   +2 more sources

Gravitational Lensing by Elliptical Galaxies [PDF]

Symposium - International Astronomical Union, 2002
The probability that high-redshift quasars are gravitationally-lensed by intervening galaxies increases rapidly with the cosmological constant, ΩΛ0 (whilst being only weakly dependent on the density parameter, Ωm0), and the low number of lenses observed implies that ΩΛ0 ≲ 0.7 (e.g. Kochanek 1996).
Rachel L. Webster, Daniel J. Mortlock, Daniel J. Mortlock   +2 more
openaire   +7 more sources

Compliant Robotics in Space: A Prospective Review of Soft and Deformable Systems for Space Missions

Advanced Intelligent Systems, EarlyView.
Compliant robots are increasingly becoming integral to space exploration due to their adaptability, flexibility, and lightweight design. This article reviews categories such as soft, reconfigurable, and hyper‐redundant robots and their evolving role in enhancing space missions.
Hamed Rahimi Nohooji, Holger Voos
wiley   +1 more source