A Way Forward for Cosmic Shear: Monte-Carlo Control Loops

Understand

Weak lensing by large scale structure or 'cosmic shear' is a potentially powerful cosmological probe to shed new light on Dark Matter, Dark Energy and Modified Gravity.

• It is based on the weak distortions induced by large-scale structures on the observed shapes of distant galaxies through gravitational lensing.
• While the potentials of this purely gravitational effect are great, results from this technique have been hampered because the measurement of this weak effect is difficult and limited by systematics effects.
• In particular, a demanding step is the measurement of the weak lensing shear from wide field CCD images of galaxies.