We present cosmological parameter constraints from the SFI++ galaxy peculiar velocity survey , the largest galaxy peculiar velocity sample to date .
The analysis is performed by using the gridding method developed in ( 2 ) .
We concentrate on constraining parameters which are affected by the clustering of matter : \sigma _ { 8 } and the growth index \gamma .
Assuming a concordance \Lambda CDM model we find \sigma _ { 8 } = 0.91 ^ { +0.22 } _ { -0.18 } and \gamma = 0.55 ^ { +0.13 } _ { -0.14 } after marginalising over \Omega _ { m } .
These constraints are consistent with , and have similar constraining power to , the same constraints from other current data sets which use different methods .
Recently there have been several claims that the peculiar velocity measurements do not agree with \Lambda CDM .
We find instead although a higher value of \sigma _ { 8 } and a lower value of \Omega _ { m } are preferred , the values are still consistent when compared with WMAP5 .
We note that although our analysis probes a variety of scales , the constraints will be dominated by the smaller scales , which have the smallest uncertainties .
These results show that peculiar velocity analysis is a vital probe of cosmology , providing competitive constraints on parameters such as \sigma _ { 8 } .
Its sensitivity to the derivative of growth function , particularly down to redshift zero , means it can provide a vital low redshift anchor on the evolution of structure formation .
The importance of utilising different probes with varying systematics is also an essential requirement for providing a consistency check on the best-fitting cosmological model .