New prop to probe dark energy
doi:10.1038/nindia.2009.145 Published online 30 May 2009
An Indo-Dutch team has put forward a new model to decipher the secrets of dark energy and expanding universe1. The new model which modifies Einstein's equations of motion for particles will throw some light on the nature of dark energy.
About 70 per cent of the matter in the universe is in the form of dark energy, whose identity largely remains shrouded in mystery. Models based on Einstein's theory of gravity seem inadequate to explain dark energy.
The researchers modified Einstein's equations of motion for particles and proposed a new model that also fits into brane cosmology. The central idea of brane cosmology is that the visible four dimensional universe is restricted to a brane (subspace) inside a higher-dimensional space, called the 'bulk'.
The brane cosmology itself modifies the law of gravity at cosmological scales. This new model brings along modifications of the equations governing the expansion history of the universe with additional degree of freedom to investigate for the exact nature of dark energy.
'Our model can take one back in time when the universe was around 60 per cent of its present size and at the onset of a dark energy dominated era," says Subir Ghosh, one of the researchers.
The researchers say the model can be confronted with very precise observational data obtained from Supernova Legacy Survey and Hubble Space Telescope by estimating observable quantities like age of the universe and luminosity distance.
- Das, S. et al. Generalized particle dynamics: modifying the motion of particles and branes. J. High. Energ. Phys. 115, doi: 10.1088/1126-6708/2009/04/115 (2009)