AT1 - Extended Theories of Gravity and Quantum Cosmology |
|
Speaker |
Benisty, David |
|
Coauthors |
Eduardo I. Guendelman |
| Talk Title |
Unified Dark Energy and Dark Matter from Dynamical Space Time |
|
Abstract |
A unification of dark matter and dark energy based on a dynamical space time theories is suggested. By introducing a dynamical space time vector field $\chi_\mu$ a conservation of an energy momentum tensor $T^{\mu\nu}_{(\chi)}$ is implemented. This Lagrangian formulation generalize a "Unified dark energy and dark matter from a scalar field different from quintessence" [Phys.RevD 81, 043520 (2010)] which did not considered a Lagrangian formulation. This generalization allows for the solutions found previously, but also non singular bouncing solutions that rapidly approach to the $\Lambda$CDM model. The dynamical time vector field exactly coincides with the cosmic time for the a $\Lambda$CDM solution and suffers a slight shift with respect to the cosmic time in the region close to the bounce for the bouncing non singular solutions. In addition we introduced some exponential potential which could enter into $T^{\mu\nu}_{(\chi)}$ or coupled directly to the measure $\sqrt{-g}$ which gives a possible interaction between DE and DM and gives and could explain the coincidence problem. |
|
Talk view |
|
|
|
|