Gravitational Geons in 1+1 Dimensions

TL;DR

This paper explores the existence of gravitational geons in modified 1+1 dimensional theories of gravity, suggesting they could be relevant for dark matter if such solutions exist in the early universe.

Contribution

It demonstrates that certain modified 1+1 dimensional gravity theories admit gravitational geons, unlike standard general relativity.

Findings

Geons exist in Jackiw-Teitelboim theory with R^2 and □ R corrections.

Geons also exist in theories with Lagrangians proportional to R^{2/3}.

Abstract

It is well known that general relativity does not admit gravitational geons that are stationary, asymptotically flat, singularity free and topologically trivial. However, it is likely that general relativity will receive corrections at large curvatures and the modified field equations may admit solutions corresponding to this type of geon. If geons are produced in the early universe and survive until today they could account for some of the dark matter that has been "observed" in galaxies and galactic clusters. In this paper I consider gravitational geons in 1+1 dimensional theories of gravity. I show that the Jackiw-Teitelboim theory with corrections proportional to $R^2$ and $\Box R$ admits gravitational geons. I also show that gravitational geons exist in a class of theories that includes Lagrangians proportional to $R^{2/3}$.