Time machines and traversable wormholes in modified theories of gravity

Abstract

We review recent work on wormhole geometries in the context of modified theories of gravity, in particular, in f(R) gravity and with a nonminimal curvature-matter coupling, and in the recently proposed hybrid metric-Palatini theory. In principle, the normal matter threading the throat can be shown to satisfy the energy conditions and it is the higher order curvatures terms that sustain these wormhole geometries. We also briefly review the conversion of wormholes into time-machines, explore several of the time travel paradoxes and possible remedies to these intriguing side-effects in wormhole physics.

5 pages, 2 figures; contribution to the proceedings of The Time Machine Factory, Turin, Italy, 14-20 October, 2012

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Cited by in corpus (5)

• Wormhole geometries in fourth-order conformal Weyl gravity
• Magnetic wormholes and black universes with invisible ghosts
• Black Hole Perturbations and Quasinormal Modes in Hybrid Metric-Palatini Gravity
• Holographic dual of a time machine
• Visible, invisible and trapped ghosts as sources of wormholes and black universes