###
Pedro Colín (UNAM)

"Is SIDM still a good substitute for collisionless CDM?"

ABSTRACT

In this talk, I am going to discuss the structure of halos as well
as their subhalo population in a self-interacting dark matter (SIDM) cosmology.
The cross-section per unit of particle mass, sigma, is taken constant or inversely
proportional to the relative velocity, v12. The evolution of the density and
the velocity dispersion halo profiles depends on the number of collisions per
particle, nc, which in turn depends on the average of the product of sigma and
v12. For a sigma inversely proportional to v12, this number nc is essentially
independent on halo mass. When our numerical results on central densities
or core sizes are compared with observations the constant sigma case is ruled out
at the 1sigma level. On the other hand, when our results for the velocity dependent
sigma case is compared with observations they agree within the observational errors.
We notice that this is the first time in which this case is studied in SIDM N-body
simulations.

back to the workshop page