Constraints on the Cosmological Constant from Flows and Supernovae

Preprint
Publisher Website
Google Scholar
  • 17 April 1999
Abstract
Recent measurements of the global curvature of space-time, using distant supernovae as distance indicators, favor a positive cosmological constant, associated with an accelerating universal expansion. However, these results by themselves still allow an open universe with low mass density and zero cosmological constant. We show here that this degeneracy is removed by independent constraints from galaxy peculiar velocities in our cosmological neighborhood, which provide a lower bound on the permissible mean mass density. The joint constraints from the two independent sources thus favor an unbound and nearly flat universe with comparable contributions from cosmological constant and mass density, and they rule out a low-density open universe of vanishing cosmological constant. The indicated conspiracy between the values of the cosmological constant and the mass density seems to require fine tuning that is in conflict with our common wisdom concerning the early universe.

This publication has 0 references indexed in Scilit: