Graduate Save Time with CLASS Code: Neat Trick for Background Quantity Evolution

Thread starter tsaic2808
Start date Oct 18, 2023
Tags

Cosmology quantities

Click For Summary

The discussion focuses on optimizing the CLASS code by bypassing the internal Boltzmann solver to save time when calculating background quantities. Users seek methods to directly compute background evolution without evaluating perturbations or transfer functions. The main goal is to streamline the process for those only interested in background dynamics. Suggestions include modifying the code or using specific settings to achieve this efficiency. Overall, the thread emphasizes the need for faster computations in cosmological simulations.

Oct 18, 2023

tsaic2808

Is there a neat way to "not" run the internal Boltzmann solver (for perturbations) in CLASS code and rather just solve for the background quantities? This way I can save the time otherwise spent in evaluating the perturbations and transfer functions. I am only interested in the time evolution of background quantities.

Thread 'Estimates — True Size of the Universe?'

I always thought it was odd that we know dark energy expands our universe, and that we know it has been increasing over time, yet no one ever expressed a "true" size of the universe (not "observable" universe, the ENTIRE universe) by just reversing the process of expansion based on our understanding of its rate through history, to the point where everything would've been in an extremely small region. The more I've looked into it recently, I've come to find that it is due to that "inflation"...

View full post »