Line of sight paraxial gravitational cloaking

TL;DR

This paper shows that unidirectional line of sight gravitational cloaking can occur naturally without exotic matter, potentially hiding about 1% of the universe's volume through gravitational lensing effects.

Contribution

It demonstrates that natural gravitational cloaking is possible in astronomical scenarios without exotic matter, expanding understanding of gravitational lensing phenomena.

Findings

Natural gravitational cloaking can hide up to 1% of the universe's volume.

Double gravitational lens SDSSJ0946+1006 may act as a natural cloaking device.

Unidirectional cloaking does not require exotic matter, unlike traditional models.

Abstract

Three-dimensional gravitational cloaking is known to require exotic matter and energy sources, which makes it arguably physically unrealizable. On the other hand, typical astronomical observations are performed using one-dimensional paraxial line of sight geometries. We demonstrate that unidirectional line of sight gravitational cloaking does not require exotic matter, and it may occur in multiple natural astronomical scenarios which involve gravitational lensing. In particular, recently discovered double gravitational lens SDSSJ0946+1006 together with the Milky Way appear to form a natural paraxial cloak. A natural question to ask, then, is how much matter in the universe may be hidden from view by such natural gravitational cloaks. It is estimated that the total volume hidden from an observer by gravitational cloaking may reach about 1% of the total volume of the visible universe.