SciPost Submission Page
Numerical Cosmology
by Romain Teyssier
Submission summary
| Authors (as registered SciPost users): | Romain Teyssier |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202507_00083v1 (pdf) |
| Date submitted: | July 29, 2025, 7:03 p.m. |
| Submitted by: | Romain Teyssier |
| Submitted to: | SciPost Physics Lecture Notes |
| for consideration in Collection: |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
In these lecture notes, we describe the current state-of-the-art for numerical simulations of large-scale structure and galaxy formation. Numerical simulations play a central role in the preparation and the exploitation of large-scale galaxy surveys, in which galaxies are the fundamental observational object. We first describe basic methods for collisionless N-body dynamics that enable us to model dark matter accurately by solving the Vlasov-Poisson equations. We then discuss simple methods to populate dark matter halos with galaxies, such as Halo and Sub-halo Abundance Matching techniques and baryonification techniques for capturing baryonic effects on the matter distribution. We finally describe how to model the gas component by solving the Euler-Poisson equations, focusing on the foundational assumptions behind these equations, namely local thermodynamical equilibrium, and the nature of the truncation errors of the numerical scheme, namely numerical diffusion. We show a few examples of simulations of a Milky-Way-like halo without cooling, with cooling and with star formation. We finally describe different subgrid prescriptions recently developed to model star formation, supernovae feedback and active galactic nuclei and how they impact cosmological simulations.
Current status:
Reports on this Submission
Strengths
1) The notes give a pedagogical approach to the Field of Numerical Cosmology. 2) Chapter 2 provides a good overview of the Collisionless N-Body dynamics describing difference numerical schemes; starting from direct summations, tree codes to PM/P^3M schemes. Very good references on the implementation of such schemes in various softwares has been provided. 3) Chapter 3 starts with an excellent discussion on the 'definition' of DM halos, followed by a discussion on the intricacies with locating Halo centres and abundance matching techniques to create merger trees. 4)Chapter 4 describes the numerical techniques needed to solve the hydrodynamics, with a special emphasis on grid based hydrodynamics, with an exhaustive list of references given. 5) Chapter 5 gives a great overview on the various sub grid recipes employed such as stellar feedback, star formation, Black Holes etc.
Weaknesses
1) One typo identified. 2) Although great review and an exhaustive number of citations given, maybe a small section on different bounty conditions implemented would have been great. But other wise great report.
Report
Requested changes
1)LIne 427 typo: 'thshe' - the
Recommendation
Publish (surpasses expectations and criteria for this Journal; among top 10%)
Report #1 by Shivani Deshmukh (Referee 1) on 2025-9-30 (Invited Report)
Strengths
1- The structure of the document has a coherent flow. 2- Each chapter ends by providing the reason for the next chapter. 3- The language is clear and concise. 4- All the fundamental equations and concepts have been clearly referenced and explained where needed. 5- The paper provides a good overview of the state-of-the-art of numerical cosmology.
Weaknesses
1- A few typos were spotted in the document.
Report
Requested changes
None.
Recommendation
Publish (surpasses expectations and criteria for this Journal; among top 10%)
Author: Romain Teyssier on 2025-10-15 [id 5936]
(in reply to Report 1 by Shivani Deshmukh on 2025-09-30)I fixed the many typos spotted by the referee (many thanks!) plus a few missing references.
I attached the new version here.
Attachment:
corrected_version.pdf