2010-09-28

New Directions in Modern Cosmology, day 2

Today was my first day at the meeting in Leiden, named above. It is an eclectic group, because the idea was to bring together outsiders and insiders in the whole cosmology thing and have people hash it out: A great idea. The talks were good, but I hope I will be forgiven for saying that (for my geeky self) I learned the most from the talk given by Hao Liu (Beijing), who is re-analyzing the WMAP data starting at the time stream. He is finding many very interesting things out about the calibration, attitude model, and map-making. It appears that the quadrupole amplitude is very soft. It is all about attitude and configuration modeling, just like Hipparcos, which is not surprising. Plus there are sidelobe issues. It appears that no-one, not Hou or the WMAP team, is building the full likelihood including all calibration parameters and then marginalizing out everything but the map (or the cosmological parameters). That is, there still is not an honest Bayesian analysis (if that is even possible!).

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