baryons and dark matter

At MPIA Galaxy Coffee, Bovy talked about his work on pre-reionization cosmology: He has worked out the effect that velocity differences between baryons and dark matter (just after recombination) have on structure formation: On large scales, there are velocity offsets of the order of tens of km/s at z=1000. The offsets are spatially coherent over large scales but they affect most strongly the smallest dark-matter concentrations. Right now this work doesn't have a huge impact on the "substructure problem" but it might as we go to larger samples of even fainter satellite galaxies at larger Galactocentric distances. In question period there was interest in the possible impact on the Lyman-alpha forest. In the rest of the day, Sanderson (Groningen) and I kept working on action space, and Lusso (MPIA) and I continued working on fitting quasar SEDs.