PSCz superclusters: detection, shapes and cosmological implications

We study the possibility of correctly identifying, from the smooth galaxy d ensity field of the PSCz flux-limited catalogue, high-density regions (supe rclusters) and recovering their true shapes in the presence of a bias intro duced by the coupling between the selection function and the constant radiu s smoothing. We quantify such systematic biases in the smoothed PSCz densit y field and after applying the necessary corrections we study supercluster multiplicity and morphologies using a differential geometry definition of s hape. Our results strongly suggest that filamentary morphology is the domin ant feature of PSCz superclusters. Finally, we compare our results with tho se expected in three different cosmological models and find that the Lambda cold dark matter (CDM) model (Omega (Lambda) = 1 - Omega (m) = 0.7) perfor ms better than Omega (m) = 1 CDM models.