Abstract
We analyze the interaction between dark energy and dark matter from a thermodynamical perspective. By assuming they have different temperatures, we study the possibility of occurring a decay from dark matter into dark energy, characterized by a negative parameter . We find that, if at least one of the fluids has nonvanishing chemical potential, for instance and or and , the decay is possible, where and are the chemical potentials of dark energy and dark matter, respectively. Using recent cosmological data, we find that, for a fairly simple interaction, the dark matter decay is favored with a probability of over the dark energy decay. This result comes from a likelihood analysis where only background evolution has been considered.
- Received 31 October 2008
DOI:https://doi.org/10.1103/PhysRevD.79.043517
©2009 American Physical Society