Prospects for Cosmology with Cluster Mass Profiles

We test the precision with which weak lensing data can provide characteristiccluster mass profiles within Cold Dark Matter scenarios. Using a paralleltreecode to simulate volumes as large as 500h-1 Mpc with good resolution, wegenerate samples of large clusters within a standard CDM model and an open CDMmodel with Omega_o=0.3. We mock high-quality lensing data by includingrealistic errors, selecting cluster samples based on velocity dispersion, andfitting profiles within a realistic range in radius. We find that a sample often clusters can determine logarithmic profile slopes with 1 sigma errors ofabout 7%. Increasing the sample size to twenty brings this error down to lessthan 5%, but this is still insufficient to distinguish the two models. However,measures of cluster profiles obtained with weak lensing do place strongconstraints for general CDM--like models of structure formation, and we discussthe optimal strategy for obtaining data samples to use for this purpose.