The Topology of Weak Lensing Fields

The topology of weak lensing fields is studied using the two-dimensional genus statistic. Simulated fields of the weak lensing convergence are used to study the effect of nonlinear gravitational evolution and to model the statistical errors expected in observational surveys. For large smoothing angles, the topology is in agreement with the predictions from linear theory. On smoothing angles smaller than 10', the genus curve shows the non-Gaussian signatures of gravitational clustering and differs for open and flat cold dark matter models. Forthcoming surveys with areas larger than 10 deg2 should have adequate signal-to-noise ratio to measure the non-Gaussian shape and the Ω-dependence of the genus statistic.

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