The probability distribution function (PDF) of cosmic density fluctuations: How to measure it? How to model it? What information does it contain?

Dec 09, 2019 - 11:00 am to 12:00 pm

Campus, Varian 355

Oliver Friedrich (Kavli Institute for Cosmology Cambridge)

In this talk I will lead you through the highlights of a series of papers (Gruen++2018, Friedrich++2018, Friedrich&Uhlemann et al. in prep, Uhlemann&Friedrich et al. in prep) that promote an alternative framework of studying large scale structure data: analysis of the 1-point PDF of density fluctuations. The main difference between the PDF and 2-point correlation functions is readily explained: 2-point functions measure the variance of fluctuations as a function of scale, while the PDF measures all moments of the fluctuations at one scale. But how would you ever measure the PDF in real data? How would you model it theoretically? And to what physics is it sensitive to? The talk will give a number of answers to these questions.