Cosmological Constraints from Compact Radio Source Angular Size versus Redshift Data

We use the Gurvits, Kellermann, Frey compact radio source angular size versus redshift data to place constraints on cosmological model parameters in models with and without a constant or time-variable cosmological constant. The resulting constraints are consistent with but weaker than those determined using current supernova apparent magnitude versus redshift data. Subject headings: cosmology: cosmological parameters—cosmology: observation—largescale structure of the universe 1.