Could Dark Energy be a Manifestation of Gravity?
  It is shown that so-called dark energy could possible be a manifestation of the gravitational vortex producing the "gravitomagnetic" (GM) force field: associated with cosmic matter rotation and inertial spacetime frame dragging. The general relativistic Godel-Obukhov spacetime metric which incorporates expansion and rotation of the Universe is used to evaluate this force. This metric is expressed here in spherical comoving coordinates. Through a cosmic time evolution, it is shown that cosmic acceleration is expected when the magnitude of the radial repulsive GM force exceeds that of the familiar or usual attractive gravitational "gravitoelectric" (GE) force: associated with just cosmic matter and spacetime warping (or curvature). In general, this phenomenon of cosmic accelerated expansion appears to have occurred twice in the history of the Universe: the inflationary phase and the present-day acceleration phase. It is suggested in this model that the two phases may or may not be related. The cosmological model presented here is described in the context of Einstein's Theory of General Relativity in Riemann-Cartan spacetime (the "generalized" Einstein- Cartan theory of gravity), which includes cosmic rotation, its effect of spacetime torsion, and it being considered as an intrinsic part of gravity. Also, an associated derived analytical expression for the cosmic primordial magnetic field is presented. Evolving this magnetic field over cosmic time shows it to be consistent with theory and observations. In addition, it appears that the spin density of cosmic matter couples this magnetic field to the GM field, and also couples this magnetic field to the GE field. 
Reva Kay Williams (The University of Toledo)
physics.gen-ph