Non-symmetric wormholes and localized Big Rip singularities in Einstein-Weyl gravity

TL;DR

This paper introduces a new class of non-symmetric wormholes in Einstein-Weyl gravity, featuring unique asymptotic properties and a Big Rip-like singularity, expanding the landscape of possible high-energy gravitational solutions.

Contribution

It presents novel non-symmetric wormhole solutions with Yukawa-like external potentials and Big Rip singularities, filling a large parameter space in Einstein-Weyl gravity.

Findings

New asymptotically flat wormholes with non-symmetric matching.

Wormholes can mimic black hole gravitational properties.

Existence of Big Rip-like singularities at finite proper time.

Abstract

The inclusion of the Weyl squared term in the gravitational action is one of the most simple, yet non trivial modifications to General Relativity at high energies. Nevertheless the study of the spherically-symmetric vacuum solutions of this theory has received much attention only in recent times. A new type of asymptotically flat wormhole which does not match symmetrically at a finite radius with another sheet of the spacetime is presented. The outer spacetime is characterized by a newtonian potential with a Yukawa correction, and has gravitational properties that can be arbitrarily close to the ones of a Schwarzschild black hole. The internal spacetime instead possesses a singularity at $r=\infty$ with the topology of a 2-dimensional sphere. The expansion scalar of geodesics reaching this singularity diverges in a finite amount of proper time, with a striking resemblance with the future singularity of the Big Rip cosmological scenario. In terms of the external Yukawa hair and mass $M$, these new wormholes fill a large region of the two-dimensional parameter space of physical solutions with $M>0$. On the contrary black holes, both of Schwarzschild and non-Schwarzschild nature, are confined on a line. We argue that this type of wormholes are ideal black hole mimickers.