Results of the GREAT08 Challenge: an image analysis competition for cosmological lensing

Sarah Bridle, Sreekumar T Balan, Matthias Bethge, Marc Gentile, Stefan Harmeling, Catherine Heymans, Michael Hirsch, Reshad Hosseini, Mike Jarvis, Donnacha Kirk, Thomas Kitching, Konrad Kuijken, Antony Lewis, Stephane Paulin-Henriksson, Bernhard Schölkopf, Malin Velander, Lisa Voigt, Dugan Witherick, Adam Amara, Gary Bernstein, Frédéric Courbin, Mandeep Gill, Alan Heavens, Rachel Mandelbaum, Richard Massey, Baback Moghaddam, Anais Rassat, Alexandre Réfrégier, Jason Rhodes, Tim Schrabback, John Shawe-Taylor, Marina Shmakova, Ludovic Van Waerbeke, David Wittman
July, 2010
PDF

Abstract

We present the results of the Gravitational LEnsing Accuracy Testing 2008 (GREAT08) Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new ideas by presenting the problem to researchers outside the shear measurement community. Six GREAT08 Team methods were presented at the launch of the Challenge and five additional groups submitted results during the 6-month competition. Participants analyzed 30 million simulated galaxies with a range in signal-to-noise ratio, point spread function ellipticity, galaxy size and galaxy type. The large quantity of simulations allowed shear measurement methods to be assessed at a level of accuracy suitable for currently planned future cosmic shear observations for the first time. Different methods perform well in different parts of simulation parameter space and come close to the …

Matthias Bethge
Matthias Bethge
Professor for Computational Neuroscience and Machine Learning & Director of the Tübingen AI Center

Matthias Bethge is Professor for Computational Neuroscience and Machine Learning at the University of Tübingen and director of the Tübingen AI Center, a joint center between Tübingen University and MPI for Intelligent Systems that is part of the German AI strategy.