Wormhole geometries supported by three-form fields (original) (raw)

Generic Three-Parameter Wormhole Solution in Einstein-Scalar Field Theory

Particles, 2021

An exact analytical, spherically symmetric, three-parametric wormhole solution has been found in the Einstein-scalar field theory, which covers the several well-known wormhole solutions. It is assumed that the scalar field is massless and depends on the radial coordinate only. The relation between the full contraction of the Ricci tensor and Ricci scalar has been found as RαβRαβ=R2. The derivation of the Einstein field equations have been explicitly shown, and the exact analytical solution has been found in terms of the three constants of integration. The several wormhole solutions have been extracted for the specific values of the parameters. In order to explore the physical meaning of the integration constants, the solution has been compared with the previously obtained results. The curvature scalar has been determined for all particular solutions. Finally, it is shown that the general solution describes naked singularity characterized by the mass, the scalar quantity and the throat.

Wormhole formation in massive gravity: an analytic description

The European Physical Journal C

The present study analyses the wormhole solution both in the dRGT-f(R, T) massive gravity and Einstein massive gravity. In both the models, the anisotropic pressure solution in ultrastatic wormhole geometry gives rise to the shape function that involves massive gravity parameters gamma\gammagamma γ and Lambda\LambdaLambda Λ . However, the terms consisting of gamma\gammagamma γ and Lambda\LambdaLambda Λ acts in such a way that the spacetime loses asymptotic flatness. Similar to the black hole solution in massive gravity, this inconsistency arises due to the repulsive effect of gravity which can be represented by the photon deflection angle that goes negative after a certain radial distance. It is investigated that the repulsive effect induced in the massive gravitons push the spacetime geometry so strongly that the asymptotic flatness is effected. On the other hand, in this model, one can have a wormhole with ordinary matter at the throat that satisfies all the energy conditions while the negative energ...

New wormhole solutions in a viable f (R) gravity model

International Journal of Modern Physics D

Traversable wormhole solutions in General Relativity require exotic matter sources that violate the null energy condition (NEC), and such behavior may be avoided in modified gravity. In this study, we analyze the energy conditions for static, spherically symmetric traversable Morris–Thorne wormholes in a recently proposed viable [Formula: see text] gravity model. We numerically analyze solutions considering both constant and variable redshift functions, and present wormhole spacetimes respecting the NEC, supported by a phantom energy-like equation of state for the source. Moreover, we analyze the stability of the spacetimes using the generalized Tolman–Oppenheimer–Volkov equation. We demonstrate the effects of certain parameters in the [Formula: see text] model in determining energy condition violations, and establish that stable wormholes can be formulated only at the expense of violating the NEC.