Gödel-type universes in f(T) gravity
arXiv:1203.2016 · doi:10.1142/S0218271812500745
Abstract
The issue of causality in gravity is investigated by examining the possibility of existence of the closed timelike curves in the Gödel-type metric. By assuming a perfect fluid as the matter source, we find that the fluid must have an equation of state parameter greater than minus one in order to allow the Gödel solutions to exist, and furthermore the critical radius , beyond which the causality is broken down, is finite and it depends on both matter and gravity. Remarkably, for certain models, the perfect fluid that allows the Gödel-type solutions can even be normal matter, such as pressureless matter or radiation. However, if the matter source is a special scalar field rather than a perfect fluid, then and the causality violation is thus avoided.
18 pages, introduction revised, reference added
References in corpus (17)
- Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
- Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
- Dark torsion as the cosmic speed-up
- Modified teleparallel gravity: inflation without inflaton
- Einstein's Other Gravity and the Acceleration of the Universe
- On Born-Infeld Gravity in Weitzenbock spacetime
- Cosmological perturbations in f(T) gravity
- Observational constraints on theory
- Generalizations of teleparallel gravity and local Lorentz symmetry
- models with phantom divide line crossing
- Observational information for f(T) theories and Dark Torsion
- Conformal transformation in theories
- Static Solutions with Spherical Symmetry in f(T) Theories
- Emergent universe in chameleon, f(R) and f(T) gravity theories
- Pure kinetic k-essence as the cosmic speed-up
- Gödel-type universes in f(R) gravity
- Gödel-type universes in Palatini f(R) gravity