Effect of neutrino asymmetry on the estimation of cosmological   parameters
  The recent analysis of the cosmic microwave background data carried out by the WMAP team seems to show that the sum of the neutrino masses is <0.7 eV. However, this result is not model-independent, depending on precise assumptions on the cosmological model. We study how this result is modified when the assumption of perfect lepton symmetry is dropped out. 
Massimiliano Lattanzi