A comparison of local Type Ia supernovae with the IRAS PSCz gravity field

We compare the measured peculiar velocities of 98 local (<150 h(-1) Mpc) Type Ia supernovae with predictions derived from the IRAS PSCz survey. There is excellent agreement between the two data sets, with a best- fitting beta(I)(= Omega m0.6/b(I)) of 0.55 +/- 0.06. Subsets of the supernovae data set are further analysed, and the above result is found to be robust with respect to culls by distance, host-galaxy extinction and choice of reference frame in which the analysis is carried out. Alternative methods of determining beta(I) including density-density comparisons, dipole measurements and WMAP-based results are also discussed. We conclude that most recent determinations are consistent with a value of beta(I) = 0.5.