PROSPECTS FOR COSMOLOGY WITH CLUSTER MASS PROFILES

We test the precision with which weak lensing data can provide charact eristic cluster mass profiles within cold dark matter (CDM) scenarios. Using a parallel tree code to simulate volumes as large as 500 h(-1) Mpc with good resolution, we generate samples of large clusters within a standard CDM model and an open CDM model with Ohm(0) = 0.3. We mock high-quality lensing data by including realistic errors, selecting cl uster samples based on velocity dispersion, and fitting profiles withi n a realistic range in radius. We find that a sample of 10 clusters ca n determine logarithmic profile slopes with 1 sigma errors of about 7% . Increasing the sample size to 20 brings this error down to less than 5%, but this is still insufficient to distinguish the two models. How ever, measures of cluster profiles obtained with weak lensing do place strong constraints for general CDM-like models of structure formation , and we discuss the optimal strategy for obtaining data samples to us e for this purpose.