Refreshments at 3:45pm, talk begins at 4pm

Abstract: 
Cold dark matter, along with dark energy, constitute 96% of the universe. Calculations using these components have successfully explained many aspects of structure formation, but as is appropriate for such a broad framework there have also been multiple challenges along the way.  One recent challenge involves the existence of structure in the satellite galaxy distributions of the Galaxy and M31, such as thin planes with apparent kinematic coherence, which have been claimed to be inconsistent with the results from dark matter simulations.  However, these are a posteriori claims: a pattern is seen in data, and then that particular pattern is analyzed for significance, which can easily lead to misleading assessments of improbability.  I will discuss different statistical methods to determine more objectively whether observed patterns are consistent with data, and will also discuss planned future work to help compare different models of cold dark matter.

Host:  Scott Hughes

Image: Possible thin plane of satellite galaxies of M31; Ibata et al. 2013, Nature, 493, 62