Masjedi gave a nice talk at group meeting about merging at redshift around 0.6 from COMBO-17 as estimated by Bell, and Kathryn Johnston (Columbia) gave our astro seminar on the merging history of the Milky Way and M31. There are lots of informative observations, but I haven't yet figured out a hard test of CDM.


  1. Hogg,

    If you want a hard test of CDM, you've got to be a bitch.

    Hard test of CDM...


  2. The hardest test you could make of CDM should come from galaxy-galaxy lensing, I think. There you have everything, merger rates modifying your HOD, profiles of galaxies and substructure, etc.
    To disentangle all that you may use different poupulation à la Scranton in the SDSS cosmic magnification detection.

    I can only see galaxy-galaxy lensing making the kind of tests you want to make, Hogg.