Monday, July 7, 2014 - 11:00am
Andrea V. Macciò (MPIA):
"Correlation and Causation strike back"
Abstract. Correlations between global galaxy properties, sometimes known as scaling relations, have been extensively used by both theorists and observers to better understand the path of galaxy formation. In my last blackboard colloquium I showed that correlation does not always imply causation, as for example in the case of the bulge-black hole mass relation. In this talk, I will look at the other side of the causation-correlation problem. Namely, I would like to check if a clear causal relation between two physical quantities in a given galaxy formation model always provides the expected relation between the derived observable quantities. I will demonstrate that a lot of care should be taken before drawing conclusions on the underlying physics of galaxy formation from simple scaling relations.