Domain Wall Dominated Universes

TL;DR

This paper proposes a universe model where dark matter consists of frustrated domain walls with negative pressure, potentially explaining cosmic acceleration without a cosmological constant.

Contribution

It introduces a novel dark matter component made of domain walls that can account for acceleration and flatness, differing from traditional dark matter models.

Findings

Domain wall network can serve as a significant dark matter component.

Negative pressure from domain walls can explain cosmic acceleration.

Model aligns with observations of flat universe and matter density.

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 $\Omega_{\rm dw}\approx 0.7$ can reconcile a spatially flat universe with the many observations indicating $\Omega_{\rm m}\approx 0.3.$ 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.