Till Sawala (Durham University, England)

Structure formation: not just dark matter
When Sep 27, 2013 from 03:00 PM to 04:00 PM
What
  • Special Seminar
Where SH, Lecture hall
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While collisionless simulations of cold dark matter (CDM) successfully describe the large scale evolution of structures, its apparent failures on small scales have prompted renewed interest into alternative models. I will review the principle challenges to CDM, and discuss some of the proposed solutions. Based on a comparison of numerical simulations with and without baryons, I will also discuss the impact of baryons on structure formation, and show that gas pressure, re-ionisation, supernova feedback, and truncated accretion systematically reduce the total masses and abundances of structures. In particular, I will show that accounting for the reduced mass of haloes, and for the presence of unobservable "dark" haloes, largely reconciles the CDM predictions with the observations.