Notes on wormhole existence in scalar-tensor and F(R) gravity

Abstract

Some recent papers have claimed the existence of static, spherically symmetric wormhole solutions to gravitational field equations in the absence of ghost (or phantom) degrees of freedom. We show that in some such cases the solutions in question are actually not of wormhole nature while in cases where a wormhole is obtained, the effective gravitational constant G_eff is negative in some region of space, i.e., the graviton becomes a ghost. In particular, it is confirmed that there are no vacuum wormhole solutions of the Brans-Dicke theory with zero potential and the coupling constant ω> -3/2, except for the case ω= 0; in the latter case, G_eff < 0 in the region beyond the throat. The same is true for wormhole solutions of F(R) gravity: special wormhole solutions are only possible if F(R) contains an extremum at which G_eff changes its sign.

7 two-column pages, no figures, to appear in Grav. Cosmol. A misprint corrected, references updated

References in corpus (10)

• Wormhole geometries in f(R) modified theories of gravity
• No realistic wormholes from ghost-free scalar-tensor phantom dark energy
• Wormhole throats in $R^m$ gravity
• Evolving wormhole geometries within nonlinear electrodynamics
• General class of vacuum Brans-Dicke wormholes
• Tolman-Oppenheimer-Volkoff equations in presence of the Chaplygin gas: stars and wormhole-like solutions
• Wormhole dynamics in spherical symmetry
• Nonminimal coupling for the gravitational and electromagnetic fields: Traversable electric wormholes
• Cold black holes and conformal continuations
• Once again on thin-shell wormholes in scalar-tensor gravity

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