Thursday, November 29, 2012

1211.6657 (Norman Cruz et al.)

Interacting warm dark matter    [PDF]

Norman Cruz, Guillermo Palma, David Zambrano, Arturo Avelino
We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear "lambda * rho_m^alpha * rho_e^beta" form, where rho_m and rho_e are the energy densities of the dark matter and dark energy, respectively. The parameters alpha and beta in principle are not constraint to take any particular values. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the space of the dark matter and dark energy densities. The constants (lambda, alpha, beta) as well as (w_m, w_e) of the EoS of dark matter and dark energy respectively were estimated using the cosmological observations of the type Ia supernovae data set and the Hubble parameter H(z) at different redshift. We found that the best fit to data is for a model with a phantom dark energy interacting with a warm dark matter, where the energy transfer comes from the dark energy to the dark matter and with an interacting term of the simple form "rho_m * rho_e". This result is consistent with stable solutions of the dynamical system analysis.
View original: http://arxiv.org/abs/1211.6657

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