Results 191 to 200 of about 1,077 (214)
This paper should be read as a three-scale lensing closure proposal within the Geometric Relay Programme. It explores how the relay response may connect cosmic shear, galactic lensing and cluster convergence. It is complementary to the later GRP mu-Sigma CLASS implementation, which provides the perturbative dynamical-lensing split.
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Standard astrophysics interprets the anomalous gravitational lensing of deep galactic halos and colliding clusters as definitive proof of an invisible "Dark Matter" particle. This paper demonstrates that Dark Matter is a mathematical artifact resulting from the application of continuous-field relativity to a discrete spatial matrix.
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This paper presents the first synthetic modeling test of the Relativity of Information and Geometric Principles (RIGP) framework applied to strong gravitational lensing. Using the well-characterized quad lens system SDSS J1206+4332, we superimpose an informational perturbation term Sμν onto a standard singular isothermal ellipsoid (SIE) plus ...
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Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT Recovering credible cosmological parameter constraints in a weak lensing shear analysis requires an accurate model that can be used to marginalize over nuisance parameters describing potential sources of systematic uncertainty, such as the uncertainties on the sample redshift distribution n(z).
Tianqing Zhang +2 more
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im3shape: a maximum likelihood galaxy shear measurement code for cosmic gravitational lensing [PDF]
Monthly Notices of the Royal Astronomical Society, 2013 We present and describe im3shape, a new publicly available galaxy shape measurement code for weak gravitational lensing shear. im3shape performs a maximum likelihood fit of a bulge-plus-disc galaxy model to noisy images, incorporating an applied point spread function.
J Zuntz +2 more
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Strong gravitational lensing’s ‘external shear’ is not shear
Monthly Notices of the Royal Astronomical SocietyABSTRACT The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus ‘external shear’, which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight.
Amy Etherington +2 more
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Characterizing the shapes of galaxy clusters using moments of the gravitational lensing shear
Astroparticle Physics, 2005 17 pages, 6 figures; added references, corrected typos, matches published ...
Martin White
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Weak gravitational lensing shear measurement with FPFS: analytical mitigation of noise bias and selection bias [PDF]
Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT Dedicated ‘Stage IV’ observatories will soon observe the entire extragalactic sky, to measure the ‘cosmic shear’ distortion of galaxy shapes by weak gravitational lensing. To measure the apparent shapes of those galaxies, we present an improved version of the Fourier Power Function Shapelets (FPFS) shear measurement method. This
Xiangchong Li, Yin Li, Richard Massey
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Weak gravitational lensing in the standard cold dark matter model, using an algorithm for three-dimensional shear [PDF]
Monthly Notices of the Royal Astronomical Society, 1999 We investigate the effects of weak gravitational lensing in the standard Cold Dark Matter cosmology, using an algorithm which evaluates the shear in three dimensions. The algorithm has the advantage of variable softening for the particles, and our method allows the appropriate angular diameter distances to be applied to every evaluation location within
Peter A Thomas +2 more
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Shear and magnification angular power spectra and higher-order moments from weak gravitational lensing [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 Revised in accordance with referee's report; now accepted by ...
A N Taylor, Taylor A N
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