Résumé / Abstract Journal-club_Doctorants

Séminaire Doctorants / Seminar PhD students

« The Devil in the details: epistemology of simplified sub-grid models in galaxy formation simulations »

Chi An Dong Pàez
Institut d'Astrophysique de Paris (Paris, France)

The physics of galaxy formation is strikingly complex and non-linear. The evolution of galaxies is influenced by the interplay of many different physical phenomena occurring on a wide variety of physical scales. Given the complexity of the physics at work and the sparsity of real-world data, numerical simulations have arisen as an indispensable tool in modern astrophysics. However, there are many processes that occur below the resolution scale of galaxy formation simulations but can have a strong impact on galactic scales. These processes generally need to be modelled using simplified "sub-grid" models. Sub-grid models are usually calibrated using galaxy-scale observables, such as the galaxy mass function or the galaxy-BH scaling relations. Adding subgrid models increases the realism of galaxy formation simulations, but in some cases, this comes at the cost of less predictive power and a higher degree of model complexity and epistemic opacity. How should we build our simulation models in order to maximise the scientific output while avoiding epistemic traps? In this session, I will try to review the epistemological problems arising from simplified sub-grid models in cosmological simulations and try to stir up a discussion session.
vendredi 2 février 2024 - 16:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique
Page web du Séminaire / Seminar's webpage