Dark matter and space-time symmetry restoration

TL;DR

This paper explores how global variables and space-time symmetry breaking can lead to a form of dark matter that retains memory of past global interactions, with potential observable effects in astrophysical structures.

Contribution

It introduces a mechanism where global interactions cause symmetry breaking, resulting in a legacy matter component behaving like dark matter with distinctive properties.

Findings

Global interactions degrade space-time invariance, leaving a legacy matter component.

The legacy matter acts like dark matter, with some degrees of freedom frozen.

An example shows a specific halo profile influenced by past global interactions.

Abstract

We examine local physics in the presence of global variables: variables associated with the whole of the spacelike surfaces of a foliation. These could be the (pseudo-)constants of nature and their conjugate times, but our statements are more general. Interactions between the local and the global (for example, dependence of the local action on global times dual to constants) degrades full space-time diffeomorphism invariance down to spatial diffeomorphism invariance, and so an extra degree of freedom appears. When these presumably primordial global interactions switch off, the local action recovers full invariance and so the usual two gravitons, but a legacy matter component is left over, bearing the extra degree of freedom. Under the assumption that the preferred foliation is geodesic, this component behaves like dark matter, except that 3 of its 4 local degrees of freedom are frozen, forcing its rest frame to coincide with the preferred foliation. The non-frozen degree of freedom (the number density of the effective fluid) is the survivor of the extra "graviton" present in the initial theory, and keeps memory of all the past global interactions that took place in a given location in the preferred foliation. Such "painted-on" dark matter is best distinguished from the conventional one in situations where the preferred frame would be preposterous if all 4 degrees of freedom of dark matter were available. We provide one example: an outflowing halo of legacy matter with exact escape speed at each point and a very specific profile, surrounding a condensed structure made of normal matter.