Implication of Ω[TINF][CLC][ITAL]m[/ITAL][/CLC][/TINF] through the Morphological Analysis of Weak Lensing Fields

We apply the morphological descriptions of two-dimensional contour map, theso-called Minkowski functionals (the area fraction, circumference, and Eulercharacteristics), to the convergence field $\kappa(\bm{\theta})$ of thelarge-scale structure reconstructed from the shear map produced by theray-tracing simulations. The perturbation theory of structure formation hassuggested that the non-Gaussian features on the Minkowski functionals withrespect to the threshold in the weakly nonlinear regime are induced by thethree skewness parameters of $\kappa$ that are sensitive to the densityparameter of matter, $\Omega_{\rm m}$. We show that, in the absence of noisedue to the intrinsic ellipticities of source galaxies with which theperturbation theory results can be recovered, the accuracy of $\Omega_{\rm m}$determination is improved by $\sim 20%$ using the Minkowski functionalscompared to the conventional method of using the direct measure of skewness.Comment: 4 pages, 3 figures, to appear in ApJ Lette