The rest-frame K-band luminosity function of galaxies in clusters to z=1.3

We derive the rest-frame K-band luminosity function for galaxies in 32 clusters at 0: 6 < z < 1: 3 using deep 3.6 and 4.5 mu m imaging from the Spitzer Space Telescope Infrared Array Camera. The luminosity functions approximate the stellar mass function of the cluster galaxies. Their dependence on redshift indicates that massive cluster galaxies ( to the characteristic luminosityM(K)(*)) are fully assembled at least at z similar to 1.3 and that little significant accretion takes place at later times. The existence of massive, highly evolved galaxies at these epochs is likely to represent a significant challenge to theories of hierarchical structure formation where such objects are formed by the late accretion of spheroidal systems at z < 1.