Speaker
Linus Thummel
(University of Edinburgh)
Description
Modifications of General Relativity have been widely studied to alleviate cosmological tensions. Most of these models lead to an effective strengthening of gravity and enhanced growth. However, the S8 tension - arising from weak-lensing observations that suggest less structure formation than predicted by ΛCDM - points to a different scenario.
In this talk, I will present a method to design stable modified gravity theories that reproduce a specific phenomenological trend in cosmological observations. This can be used to address the S8 tension and adapted to trends from Stage-IV surveys. Specifically, I will show how we can use machine learning processes to explore the space of Horndeski theories to find stable islands of weak gravity.
Author
Linus Thummel
(University of Edinburgh)