COT1 - Dark Energy and Universe Acceleration |
Speaker_ |
Mathews, Grant |
Co-autors |
N. Q. Lan, J. R. Wilson. C. Kolda |
Talk _ |
Dark Energy and Decaying Dark Matter |
Abstract _ |
We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We show that such decays can lead naturally to a negative pressure term in the cosmic energy-momentum tensor and is a candidate for dark energy. We derive the modified cosmic equations of motion for this fluid and show that if dark matter particles decay at the late times and on a short timescale compared to the present hubble time than an epoch of cosmic acceleration is produced without vacuum enbergy. As a illustration , we investigate the effects of decaying cold dark matter in a Lambda = 0, flat, initially matter dominated cosmology. We show that this model satisfies the cosmological constraint from Type Ia supernovae at high redshift. Possible candidates for drcaying and additional observational tests of this new cosmological paradigm are suggested. |