Domain Wall Dominated Universes

Abstract

We consider a cosmogony with a dark matter component consisting of a network of frustrated domain walls. Such a network provides a solid dark matter component with $p=-(2/3)\rho$ that remains unclustered on small scales and with ${\Omega }_{\mathrm{dw}}\approx 0.7$ can reconcile a spatially flat universe with the many observations indicating ${\Omega }_{\mathrm{m}}\approx \mathrm{0.3.}$ Because of its large negative pressure, this component can explain the recent observations indicating an accelerating universe without recourse to a non-vanishing cosmological constant. We explore the viability of this proposal and prospects for distinguishing it from other kinds of proposed dark matter with significant negative pressure.

5 pages revtex with three embedded postscript figures. Minor mistakes corrected