About the traversability of thin-shell wormholes

Abstract

Traversability in relation with tides across thin-shell wormholes is analyzed. Conditions for a safe travel through a wormhole throat are established in terms of the parameters characterizing the geometries and reasonable assumptions regarding the travellers motion. Most convenient geometries turn to include the physically interesting example of wormholes connecting locally flat submanifolds as those associated to gauge cosmic strings. A certain relaxation of the conditions imposed and the corresponding extension of the set of admissible configurations is also briefly discussed.

Further considerations about the traversability of thin-shell wormholes

“…With these definitions, we can recall the result of [1] for the radial tide of a radially moving object ∆a = R r0 r0…”

“…These results would seem to rule out the possibility of a safe passage through such configurations. However, in our previous work [1] we briefly introduced an alternative point of view, in the spirit of taking the formal results as a first approximation to more realistic situations in which shells have a non vanishing -though still very little-thickness. Within this understanding of the problem, here we will investigate the conditions to, at least, reduce the jump of the components of the extrinsic curvature across the shell; when such reduction is possible, we will also evaluate the effects of these conditions on the curvature of the smooth regions.…”

Generalised Ellis-Bronnikov Wormholes in $f(R)$ Gravity

“…Kuhfitting addressed two fundamental issues concerning Morris-Throne wormholes in the five-dimensional spacetime, such as the origin of exotic matter and frequently inexplicable enormous radial tension at the throat [68]. Conditions for safe travel through a thin-shell wormhole throat are analyzed in [69]. The above literature discussed the static symmetric spacetime, whereas the generalization of such metric has been explored mainly in general relativity.…”

Further considerations about the traversability of thin-shell wormholes

“…The recent study in [1] shows that the main difficulty with tides across the throat of thin-shell wormholes does not come from the contribution of the smooth parts of the geometries: for points along both the radial or an angular direction, the corresponding effects are finite and proportional to the spatial separation of these points, and could be controlled by an appropriate choice of the parameters defining the metrics at each side of the shell placed at the throat radius (see also Ref. [2]).…”

“…These results would seem to rule out the possibility of a safe passage through such configurations. However, in our previous work [1] we briefly introduced an alternative point of view, in the spirit of taking the formal results as a first approximation to more realistic situations in which shells have a non vanishing -though still very little -thickness.…”