Jan Hartlap

Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS (2009)

Schrabback, Tim, Hartlap, Jan, Joachimi, Benjamin, Kilbinger, Martin, Simon, Patrick, Benabed, Karim, ...

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 PSF, and improved...

Unfolding the matter distribution using 3-D weak gravitational lensing (2009)

Simon, Patrick, Taylor, Andy, Hartlap, Jan

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 is the...

Constrained correlation functions (2009)

Schneider, Peter, Hartlap, Jan

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 statistically...

Dependence of cosmic shear covariances on cosmology - Impact on parameter estimation (2008)

Eifler, Tim, Schneider, Peter, Hartlap, Jan

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 from simulations),...

Strong lensing optical depths in a LCDM universe II: the influence of the stellar mass in galaxies (2007)

Hilbert, Stefan, White, Simon D. M., Hartlap, Jan, Schneider, Peter

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 through the...

Strong lensing optical depths in a \LambdaCDM universe (2007)

Hilbert, Stefan, White, Simon D. M., Hartlap, Jan, Schneider, Peter

We investigate strong gravitational lensing in the concordance $\Lambda$CDM cosmology by carrying out ray-tracing along past light cones through the Millennium Simulation, the largest simulation of...