CLASS + SONG Workshop

Workshop

When

  • – ET

  • – ET

For the communities working on theoretical and observational cosmology, especially on the CMB and Large Scale Structures, Einstein-Bolztmann solvers are essential tools. However, due to their complexity, they can be slightly intimidating – especially when it comes to the most interesting tasks of modifying them, implementing new physics, adding new observables, or including effects at second order in perturbation theory.

CLASS1 (by J. Lesgourgues & T. Tram) is one of the best known public Einstein-Bolztmann solvers used worldwide. It is meant to be friendly and flexible enough for serving as a starting point to any kind of extension and modification. It is written in plain C, and wrapped with C++ and python. It has been thoroughly tested since its release in 2011, and it is still undergoing significant developments in the directions of new physics, more modern algorithms and new applications. The public code SONG2 (by Fidler & Pettinari) is the extension of CLASS to the (considerably richer) level of second-order perturbation theory. Despite existing on-line material (courses, documentation, exercises), reaching the level of advanced user or developer for these codes remains a significant investment of time. The goal of this workshop is to provide a solid introduction that will speed up the mastering of the codes by the participants.

Zoom Link

July 15, 2019

CLASS Basics: Coding spirit and general rules

July 15, 2019

CLASS Exercises I: Extracting and plotting various quantities

July 15, 2019

CLASS Theory: Less trivial aspects of the implemented linear perturbation theory

July 15, 2019

SONG Theory: Second order perturbation theory and its signatures in the CMB

July 15, 2019

CLASS Usage II: Exploring the code’s possibilities through python notebooks

July 15, 2019

CLASS Usage I: From interactive runs to python notebooks

July 16, 2019

CLASS Coding II: How to implement new physics and new ingredients

July 16, 2019

CLASS Exercises II: Modifying the code

July 16, 2019

SONG Exercises: Calculating second-order perturbations

July 16, 2019

SONG Usage: Concept and structure of SONG

July 16, 2019

CLASS Coding I: Essential rules and conventions specific to the code

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