Cosmology with Multiple Galaxies
Abstract
Recent works have discovered a relatively tight correlation between Ωm and the properties of individual simulated galaxies. Because of this, it has been shown that constraints on Ωm can be placed using the properties of individual galaxies while accounting for uncertainties in astrophysical processes such as feedback from supernovae and active galactic nuclei. In this work, we quantify whether using the properties of multiple galaxies simultaneously can tighten those constraints. For this, we train neural networks to perform likelihood-free inference on the value of two cosmological parameters (Ωm and σ 8) and four astrophysical parameters using the properties of several galaxies from thousands of hydrodynamic simulations of the CAMELS project. We find that using properties of more than one galaxy increases the precision of the Ωm inference. Furthermore, using multiple galaxies enables the inference of other parameters that were poorly constrained with one single galaxy. We show that the same subset of galaxy properties are responsible for the constraints on Ωm from one and multiple galaxies. Finally, we quantify the robustness of the model and find that without identifying the model range of validity, the model does not perform well when tested on galaxies from other galaxy formation models.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2024
- DOI:
- 10.3847/1538-4357/ad4969
- arXiv:
- arXiv:2309.12048
- Bibcode:
- 2024ApJ...969..105C
- Keywords:
-
- Cosmological parameters;
- Galaxy properties;
- Galaxy processes;
- Computational methods;
- Astronomy data analysis;
- 339;
- 615;
- 614;
- 1965;
- 1858;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 13 pages, 7 figures