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We perform a weak lensing analysis on a previously reported dark-lens candidate on STIS Parallel data (Miralles et al. 2002). New VLT-data indicate that the reported signal originates from a small number of galaxies tangentially aligned towards the center of the STIS field but no signature for an extended mass distribution is found. We argue that we should be able to detect a massive cluster ($Mgeq 3.2times 10^{14}M_{odot}$) through its lensing signal up to a redshift of $zapprox 0.6$ with our data. Also the double image hypothesis of two galaxies with very similar morphologies in the STIS data is ruled out with colour information.
We report the serendipituous discovery of a conspicuous alignment of galaxies in a field obtained through the STIS Parallel Shear Survey. This project collects randomly distributed 50 x 50 fields to investigate the cosmic shear effect on this scale.
We study the estimators of various second-order weak lensing statistics such as the shear correlation functions xi_pm and the aperture mass dispersion <M_ap^2> which can directly be constructed from weak lensing shear maps. We compare the efficiency
Coupled cosmologies can predict values for the cosmological parameters at low redshifts which may differ substantially from the parameters values within non-interacting cosmologies. Therefore, low redshift probes, as the growth of structure and the d
Using publicly available code and data, we present a systematic study of projection biases in the weak lensing analysis of the first year of data from the Dark Energy Survey (DES) experiment. In the analysis we used a $Lambda$CDM model and three two-
We show that the so-called post-Born effects of weak lensing at 4th order are equivalent to lens-lens couplings in the Born Approximation. We demonstrate this by explicitly showing the equivalence of the canonical weak lensing approach at 4th order u