Address historical constraints using substructure arguments

[wadawson]

(iii) Those that compared the amount of substructure in simulated SIDM halos with the amount observed in galaxies and galaxy clusters (Hogan & Dalcanton, 2000; Yoshida et al., 2000a; Gnedin & Ostriker, 2001; Col��n et al., 2002). As the SIDM cross-section increases subhalos begin to evaporate in their parent DM halo.

Dave comments: "Is this only for very large sigma? I thought SIDM did not cause halo evaporation."

Upon a quick review I find that:
n the case of Hogan & Dalcanton they constrained sigma/m < 10,000 cm^2/g.

Gnedin & Ostriker claim a constraint of <0.3 cm^2/g

Colin et al claim <0.5 cm^2/g

These are relatively tight constraints so I should investigate the discrepancy between these findings and the current findings that SIDM does not significantly diminish the number of subhalos.