Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS Export

@article{citeulike:6058320, abstract = {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 modelling of charge-transfer inefficiency, we measure a lensing signal which is consistent with pure gravitational modes and no systematics. We carefully estimate the statistical uncertainty from simulated COSMOS-like fields obtained from ray-tracing through the Millennium Simulation. We test our pipeline on simulated space-based data, recalibrate non-linear power spectrum corrections using the ray-tracing, employ photometric redshifts to reduce potential contamination by intrinsic galaxy alignments, and marginalize over systematic uncertainties. We find that the lensing signal scales with redshift as expected from General Relativity for a concordance LCDM cosmology, including the full cross-correlations between different redshift bins. For a flat LCDM cosmology, we measure sigma\_8(Omega\_m/0.3)^0.51=0.75+-0.08 from lensing, in perfect agreement with WMAP-5, yielding joint constraints Omega\_m=0.266+0.025-0.023, sigma\_8=0.802+0.028-0.029 (all 68\% conf.). Dropping the assumption of flatness and using HST Key Project and BBN priors only, we find a negative deceleration parameter q\_0 at 94.3\% conf. from the tomographic lensing analysis, providing independent evidence for the accelerated expansion of the Universe. For a flat wCDM cosmology and prior w in [-2,0], we obtain w\<-0.41 (90\% conf.). Our dark energy constraints are still relatively weak solely due to the limited area of COSMOS. However, they provide an important proof of concept for future missions such as Euclid or JDEM, which will deliver precision dark energy constraints from potentially more than 10 000 times larger space-based surveys. (abridged)}, archivePrefix = {arXiv}, author = {Schrabback, Tim and Hartlap, Jan and Joachimi, Benjamin and Kilbinger, Martin and Simon, Patrick and Benabed, Karim and Brada\v{c}, Maru\v{s}a and Eifler, Tim and Erben, Thomas and Fassnacht, Christopher D. and High, F. William and Hilbert, Stefan and Hildebrandt, Hendrik and Hoekstra, Henk and Kuijken, Konrad and Marshall, Phil and Mellier, Yannick and Morganson, Eric and Schneider, Peter and Semboloni, Elisabetta and Van Waerbeke, Ludovic and Velander, Malin}, citeulike-article-id = {6058320}, citeulike-linkout-0 = {http://arxiv.org/abs/0911.0053}, citeulike-linkout-1 = {http://arxiv.org/pdf/0911.0053}, day = {2}, eprint = {0911.0053}, keywords = {expansion, lensing, weak}, month = {Nov}, posted-at = {2009-11-03 07:42:17}, priority = {2}, title = {Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS}, url = {http://arxiv.org/abs/0911.0053}, year = {2009} }

TY - JOUR ID - citeulike:6058320 L3 - citeulike-article-id:6058320 N2 - 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 modelling of charge-transfer inefficiency, we measure a lensing signal which is consistent with pure gravitational modes and no systematics. We carefully estimate the statistical uncertainty from simulated COSMOS-like fields obtained from ray-tracing through the Millennium Simulation. We test our pipeline on simulated space-based data, recalibrate non-linear power spectrum corrections using the ray-tracing, employ photometric redshifts to reduce potential contamination by intrinsic galaxy alignments, and marginalize over systematic uncertainties. We find that the lensing signal scales with redshift as expected from General Relativity for a concordance LCDM cosmology, including the full cross-correlations between different redshift bins. For a flat LCDM cosmology, we measure sigma_8(Omega_m/0.3)^0.51=0.75+-0.08 from lensing, in perfect agreement with WMAP-5, yielding joint constraints Omega_m=0.266+0.025-0.023, sigma_8=0.802+0.028-0.029 (all 68% conf.). Dropping the assumption of flatness and using HST Key Project and BBN priors only, we find a negative deceleration parameter q_0 at 94.3% conf. from the tomographic lensing analysis, providing independent evidence for the accelerated expansion of the Universe. For a flat wCDM cosmology and prior w in [-2,0], we obtain w<-0.41 (90% conf.). Our dark energy constraints are still relatively weak solely due to the limited area of COSMOS. However, they provide an important proof of concept for future missions such as Euclid or JDEM, which will deliver precision dark energy constraints from potentially more than 10 000 times larger space-based surveys. (abridged) TI - Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS KW - expansion KW - lensing KW - weak AU - Schrabback, Tim AU - Hartlap, Jan AU - Joachimi, Benjamin AU - Kilbinger, Martin AU - Simon, Patrick AU - Benabed, Karim AU - Bradač, Maruša AU - Eifler, Tim AU - Erben, Thomas AU - Fassnacht, Christopher AU - High, William AU - Hilbert, Stefan AU - Hildebrandt, Hendrik AU - Hoekstra, Henk AU - Kuijken, Konrad AU - Marshall, Phil AU - Mellier, Yannick AU - Morganson, Eric AU - Schneider, Peter AU - Semboloni, Elisabetta AU - Van Waerbeke, Ludovic AU - Velander, Malin PY - 2009/Nov/02/ UR - http://arxiv.org/abs/0911.0053 ER -