Cosmic inflation and big bang interpreted as explosions

TL;DR

This paper demonstrates that cosmic redshift and galaxy recession can be interpreted either as space expansion or as motion of matter through space, by constructing alternative coordinate systems within general relativity.

Contribution

It introduces 'explosion coordinates' showing that cosmic phenomena can be explained without space expansion, offering a new perspective on the big bang and inflation.

Findings

Redshift can be explained by Doppler and gravitational shifts in explosion coordinates.

Small objects do not participate in cosmic expansion in these coordinates.

The two interpretations of cosmic expansion can be reconciled.

Abstract

It has become common understanding that the recession of galaxies and the corresponding redshift of light received from them can only be explained by an expansion of the space between them and us. In this paper, for the presently favored case of a universe without spatial curvature, it is shown that this interpretation is restricted to comoving coordinates. It is proven by construction that within the framework of general relativity other coordinates exist in relation to which these phenomena can be explained by a motion of the cosmic substrate across space, caused by an explosion like big bang or by inflation preceding an almost big bang. At the place of an observer, this motion occurs without any spatial expansion. It is shown that in these "explosion coordinates" the usual redshift comes about by a Doppler shift and a subsequent gravitational shift. Making use of this interpretation, it can easily be understood why in comoving coordinates light rays of short spatial extensions expand and thus constitute an exemption from the rule that small objects up to the size of the solar system or even galaxies do not participate in the expansion of the universe. It is also discussed how the two interpretations can be reconciled with each other.