Einstein-Gauss-Bonnet traversable wormholes satisfying the weak energy condition

Abstract

In this paper, we explore higher-dimensional asymptotically flat wormhole geometries in the framework of Gauss-Bonnet (GB) gravity and investigate the effects of the GB term, by considering a specific radial-dependent redshift function and by imposing a particular equation of state. This work is motivated by previous assumptions that wormhole solutions were not possible for the k = 1 and α < 0 case, where k is the sectional curvature of an (n − 2)-dimensional maximally symmetric space, and α is the Gauss-Bonnet coupling constant. However, we emphasize that this discussion is purely based on a nontrivial assumption that is only valid at the wormhole throat, and cannot be extended to the entire radial-coordinate range. In this work, we provide a counterexample to this claim, and find for the first time specific solutions that satisfy the weak energy condition throughout the entire spacetime, for k = 1 and α < 0. In addition to this, we also present other wormhole solutions which alleviate the violation of the WEC in the vicinity of the wormhole throat.

Static spherically symmetric wormholes in f(R, T) gravity

“…Our results are consistent with the work already available in the literature [55,56]. Our results are also similar to that obtained in simple f (R) gravity [35] (that is, the case λ = 0).…”

Existence of static wormholes in f(𝒢,T) gravity

“…In f (G, T ) gravity, we find that massive test particles follow the non-geodesic trajectories due to the presence of an extra force [4]. The above inequalities (14) with T eff αβ provide the null, weak, strong (SEC) and dominant (DEC) energy conditions as…”

“…Sharif and Rani [13] studied static spherically symmetric WH solutions for exponential as well as logarithmic forms of generalized teleparallel gravity and found that WEC is violated in galactic halo region for both models. Mehdizadeh et al [14] discussed realistic traversable WH solutions in Einstein GB gravity. We have explored WH geometries for traceless, isotropic as well as barotropic matter distributions and concluded that realistic WH solutions exist in f (G) gravity only for radial barotropic fluid [15].…”

Palatini wormholes and energy conditions from the prism of general relativity

“…In fact, a plethora of wormhole solutions beyond GR have been found in a variety of theories, such as in conformal Weyl gravity [58], Kaluza–Klein [59–61], Brans–Dicke [62–65], Gauss–Bonnet [66–69], Lovelock [70, 71] braneworlds [62, 72–74], Hor̆ava–Lifshitz [75, 76], Eddington-inspired Born–Infeld [77–79], metric [80–83] and Palatini [84, 85] approaches of f ( R ) gravity and extensions [86–88], the modified teleparalellism framework [89, 90] or Einstein–Cartan theory [91]. …”