Dynamical wormholes in Einstein–Gauss–Bonnet gravity

Abstract

In the present work, we investigate evolving wormhole configurations in higher-dimensions, by adding a Gauss-Bonnet term to the standard Einstein-Hilbert action. Using a generalized Friedmann-Robertson-Walker spacetime, we derive evolving wormhole geometries by considering a constraint on Ricci scalar. In standard cosmological models, the Ricci scalar is independent of radial coordinate r and is only a function of time. We use this property to introduce a particular class of wormhole solutions for which microscopic wormholes may have been enlarged to macroscopic sizes in an expanding inflationary cosmological background. We find, for the first time, specific solutions that satisfy the weak energy condition (WEC) throughout the entire spacetime in four dimensions. In addition to this, we also present other wormhole solutions that satisfy the WEC throughout their respective evolution.

Dynamical wormholes in Lovelock gravity

“…One can check that for β = 0, the solution of Eq. ( 29) reduces to the scale factor for a higher dimensional in Gauss-Bonnet gravity [62]. In the following subsections, with the help of the master equation ( 29), we will determine the behavior of the scale factor and the related properties of the energy conditions for the wormhole geometry in the presence of Lovelock gravity.…”

Non-exotic wormholes in 4-D Einstein-Gauss-Bonnet gravity

“…He suggested that the exotic matter is not required for the existence of such WH and some of them are linearly stable. Recently, Mehdizadeh [73] investigated dynamical wormholes in Einstein-Gauss-Bonnet gravity by using specific shape function and scale factor R(t). He obtained wormhole solutions that obey the weak energy conditions.…”

Bronnikov-like Wormholes in Einstein-Scalar Gravity

“…In the massless limit, the Bronnikov solution reduces to the Ellis solution. Since then, many new wormhole solutions have been constructed in Einstein gravity or modified gravity theories [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45].…”