Manolis Papastergis - March 3, 2016

The too-big-to-fail problem is too-persistent-to-die: new constraints from
nearby field dwarfs

The "too big to fail" (TBTF) problem is a pressing observational challenge
to the standard cosmological model at small scales. Put simply, it refers
to the fact that it is very challenging to explain both the internal
kinematics and the observed number density of dwarfs in the LCDM context.
Even though the problem was first identified in the satellite population
of the Milky Way, it has now become clear that it concerns dwarf galaxies
in general. In this talk, I first plan to give an overview of the
observational evidence that supports the statements above. I then plan to
briefly describe the most promising solutions to the problem, including a
"baryonic" solution within LCDM as well as alternative dark matter models.
I will conclude by showing how present and future observations of HI in
nearby field dwarfs can help us distinguish between a cosmological and an
astrophysical solution for TBTF.