Wormhole solutions with NUT charge in higher curvature theories

Abstract

We present wormholes with a Newman-Unti-Tamburino (NUT) charge that arise in certain higher curvature theories, where a scalar field is coupled to a higher curvature invariant. For the invariants we employ i) a Gauss-Bonnet term and ii) a Chern-Simons term, which then act as source terms for the scalar field. We map out the domain of existence of wormhole solutions by varying the coupling parameter and the scalar charge for a set of fixed values of the NUT charge. The domain of existence for a given NUT charge is then delimited by the set of scalarized nutty black holes, a set of wormhole solutions with a degenerate throat and a set of singular solutions.

Traversable wormholes in beyond Horndeski theories

“…The most intensely studied approach however is the one according to which the energy conditions are violated not by the actual matter but by an effective energy-momentum tensor arising in the context of a modified theory of gravity. These theories include f (R) theories [45][46][47][48][49][50], extra dimensions [51][52][53], brane-world models [54][55][56][57][58], non-minimally coupled scalar-tensor theories [59][60][61][62][63], or higher-derivative gravitational theories [64][65][66][67][68][69][70][71][72] to mention a few indicative works. The stability behaviour of the wormhole solutions emerging in the context of different theories has also undergone an intensive study over the years [73][74][75][76][77][78] resulting at times to no-go theorems [79,80] and forcing us to move to theories beyond GR for viable solutions.…”