Precision of diffuse 21-cm lensing

Understand

We study the limits of accuracy for weak lensing maps of dark matter using diffuse 21-cm radiation from the pre-reionization epoch using simulations.

• We improve on previous "optimal" quadratic lensing estimators by using shear and convergence instead of deflection angles.
• We find that non-Gaussianity provides a limit to the accuracy of weak lensing reconstruction, even if instrumental noise is reduced to zero.
• The best reconstruction result is equivalent to Gaussian sources with effectively independent cell of side length 2.0/h Mpc.