Stats4Grads: Calibrating the Universe: an Uncertainty Analysis for a Galaxy Formation Simulation
8 October 2008 14:15 in CM105
Abstract: Many scientific areas now employ large physical computer simulations in order to understand complex real world systems. Such simulations contain a large number of input and output parameters and this leads to several problems of interest. A subset of the outputs can be compared with observed data of the real system, and a natural question to ask is: which choices of input parameters to the model will give rise to `acceptable' matches between the outputs and the data. This is known as Calibration and is one of the most important problems when dealing with models of this size and complexity.
I will describe a version of Calibration known as History Matching in the context of a Galaxy Formation simulation that attempts to model the evolution of one million galaxies from the beginning of the Universe until the present day. I will describe the process of Emulation (the statistical modelling of a deterministic function) and the method of History Matching via an Implausibility measure. Communicating the results of a successful Calibration is also a non-trivial matter as this involves describing a complex shape in a high-dimensional space, so various visualisation issues and techniques will also be discussed.
This seminar is for Postgraduate Students and Postdoctoral Researchers only
See the Stats4Grads page for more details about this series.