Contributions to the Local Gravitational Field From Beyond the Virgo Supercluster

Abstract

In the last decade, the inter-relation between the density structure and velocity perturbations in the local Virgo Supercluster (VSC) has provided a major means of determining the cosmological density parameter Ω. The underlying dynamics, the so-called Virgocentric Flow Model (VFM), assumes that the relevant peculiar gravitational field in the VSC is dominated by the monopole term, due to material inside the VSC. Over the past year, however, this premise has been called into question, on both observational and theoretical grounds. It has become clear that the contributions to the local gravitational field from beyond the VSC cannot be neglected. The major new developments are summarized here. A more detailed review is given elsewhere (Yahil 1987).