July 9, 2020 to January 31, 2025
Europe/Zurich timezone

Dear colleagues,


We would like to invite you to take part in the upcoming 135th Copernicus Webinars.


Time:              13th June, Tuesday, at 3 pm CEST (9 pm Beijing, 10pm JST, 9 am EDT)


Speaker:         Sébastien Renaux-Petel (Paris, Inst. Astrophys.)



Some directions for the future of primordial non-Gaussianities



The field of primordial non-Gaussianities is twenty years old. During that time, cosmologists have built a dictionary between the physics active during inflation and higher-order correlation functions of primordial density fluctuations. I will argue that this dictionary is far from complete, with theoretical predictions available only in restricted classes of theories.  

To fill in this gap, I will present the cosmological flow, a complete and systematic approach to compute inflationary correlators for all inflationary theories. This enables to assist our theoretical understanding and to generate theoretical data for an unbiased interpretation of upcoming cosmological observations.

I will show that the cosmological collider signal, lying in soft limits of correlators, often described as a robust probe of the field content of inflation, is as robust as its assumptions are restrictive, and I will show its properties in theories involving multiple degrees of freedom, with strong mixing, in the presence of features.

Eventually, I will explain that if equilateral non-Gaussianities are detected, there exists a natural next observational target, the low-speed collider signal, manifesting as a peculiar resonance in mildly-soft kinematical configurations.


This series is co-organised by the cosmology groups in the following institutions (in alphabetical order): 

Harvard University, Hong Kong University of Science and Technology, Institut d'Astrophysique de Paris, Institute of Physics of the Czech Academy of Science, Jagiellonian University, Kyoto University, Leiden University, Ludwig Maximilians University, McGill University, Perimeter Institute, Polish Society on Relativity, The Pennsylvania State University, The University of Tokyo, Tsinghua University, University of Geneva, University of Groningen, University of Science and Technology of China, University of Waterloo.

Science Organising Committee members (in alphabetical order):

Niayesh Afshordi, Robert Brandenberger, Yifu Cai, Xingang Chen, Ema Dimastrogiovanni, Ruth Durrer, Ghazal Geshnizjani, Chunshan Lin, Jerome Martin, Jakub Mielczarek, Viatcheslav Mukhanov, Shinji Mukohyama, Subodh Patil, Misao Sasaki, Sarah Shandera, Wei Song, Alexander Vikman, Yi Wang, Zhong-Zhi Xianyu