Determination of cosmology and evolution from K-band magnitude–redshift and number count observations

We determine cosmological and evolutionary parameters from the 3CR K -band Hubble diagram and K -band number counts, assuming that the galaxies in question undergo pure luminosity evolution. Separately the two data sets are highly degenerate with respect to choice of cosmological and evolutionary parameters, but in combination the degeneracy is resolved. Of models that either are flat or have  Ω_Λ=0  , the preferred ones are close to the canonical case  Ω_{cold  matter}=1  ,  Ω_Λ=0  , with luminosity evolution amounting to 1 mag brighter at   z =1  .