Publications (11)
Effects of large-scale structure on the accuracy of weak lensing mass measurements
Henk Hoekstra, Jan Hartlap, Stefan Hilbert +1
Weak gravitational lensing has become an important method to determine the masses of galaxy clusters. The intrinsic shapes of the galaxies are a dominant source of uncertainty, but…
Dependence of cosmic shear covariances on cosmology - Impact on parameter estimation
Tim Eifler, Peter Schneider, Jan Hartlap
In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or fr…
Strong lensing optical depths in a LCDM universe II: the influence of the stellar mass in galaxies
Stefan Hilbert, Simon D. M. White, Jan Hartlap +1
We investigate how strong gravitational lensing in the concordance LCDM cosmology is affected by the stellar mass in galaxies. We extend our previous studies, based on ray-tracing…
Probing Satellite Halos with Weak Gravitational Lensing
Bryan R. Gillis, Michael J. Hudson, Stefan Hilbert +1
We demonstrate the possibility of detecting tidal stripping of dark matter subhalos within galaxy groups using weak gravitational lensing. We have run ray-tracing simulations on ga…
Strong lensing optical depths in a \LambdaCDM universe
Stefan Hilbert, Simon D. M. White, Jan Hartlap +1
We investigate strong gravitational lensing in the concordance CDM cosmology by carrying out ray-tracing along past light cones through the Millennium Simulation, the largest s…
Cosmic shear covariance: The log-normal approximation
Stefan Hilbert, Jan Hartlap, Peter Schneider
[Abridged] We seek approximations to the cosmic shear covariance that are as easy to use as the common approximations based on normal statistics, but yield more accurate covariance…
A bias in cosmic shear from galaxy selection: results from ray-tracing simulations
Jan Hartlap, Stefan Hilbert, Peter Schneider +1
We identify and study a previously unknown systematic effect on cosmic shear measurements, caused by the selection of galaxies used for shape measurement, in particular the rejecti…
Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS
Tim Schrabback, Jan Hartlap, Benjamin Joachimi +19
We present a tomographic cosmological weak lensing analysis of the HST COSMOS Survey. Applying our lensing-optimized data reduction, principal component interpolation for the ACS P…
Weak lensing from space: first cosmological constraints from three-point shear statistics
Elisabetta Semboloni, Tim Schrabback, Ludovic van Waerbeke +3
We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-moments of the cosmic shear field, estimated from about 450,000 galaxies wit…
Unfolding the matter distribution using 3-D weak gravitational lensing
Patrick Simon, Andy Taylor, Jan Hartlap
Combining redshift and galaxy shape information offers new exciting ways of exploiting the gravitational lensing effect for studying the large scales of the cosmos. One application…
Constrained correlation functions
Peter Schneider, Jan Hartlap
We show that correlation functions have to satisfy contraint relations, owing to the non-negativity of the power spectrum of the underlying random process. Specifically, for any st…