PSCz superclusters:: detection, shapes and cosmological implications

We study the possibility of correctly identifying, from the smooth galaxy density field of the PSCz flux-limited catalogue, high-density regions (superclusters) and recovering their true shapes in the presence of a bias introduced by the coupling between the selection function and the constant radius smoothing. We quantify such systematic biases in the smoothed PSCz density field and after applying the necessary corrections we study supercluster multiplicity and morphologies using a differential geometry definition of shape. Our results strongly suggest that filamentary morphology is the dominant feature of PSCz superclusters. Finally, we compare our results with those expected in three different cosmological models and find that the Lambda cold dark matter (CDM) model (Omega (Lambda) = 1 - Omega (m) = 0.7) performs better than Omega (m) = 1 CDM models.