Editing Astronomy (section)

== Theoretical astronomy ==
{{Nucleosynthesis}}
{{Main|Theoretical astronomy}}
Theoretical astronomers use several tools including [[mathematical model|analytical models]] and [[computation]]al [[Numerical analysis|numerical simulations]]; each has its particular advantages. Analytical models of a process are better for giving broader insight into the heart of what is going on. Numerical models reveal the existence of phenomena and effects otherwise unobserved.<ref>{{cite journal|first=H.|last=Roth|title=A Slowly Contracting or Expanding Fluid Sphere and its Stability|journal=Physical Review |volume=39|issue=3|pages=525–29|date=1932|doi=10.1103/PhysRev.39.525|bibcode = 1932PhRv...39..525R }}</ref><ref>{{cite journal |first=A.S.|last=Eddington|title=Internal Constitution of the Stars|journal=Science|publisher=Cambridge University Press|date=1926|volume=52|issue=1341|pages=233–40|doi=10.1126/science.52.1341.233|url=https://books.google.com/books?id=hJW3JbhnFQMC&pg=PA182|isbn=978-0-521-33708-3|pmid=17747682|bibcode=1920Sci....52..233E |bibcode-access=free |access-date=4 November 2020|archive-date=17 August 2021|archive-url=https://web.archive.org/web/20210817020341/https://books.google.com/books?id=hJW3JbhnFQMC&pg=PA182|url-status=live}}</ref>

Theorists in astronomy endeavor to create theoretical models that are based on existing observations and known physics, and to predict observational consequences of those models. The observation of phenomena predicted by a model allows astronomers to select between several alternative or conflicting models. Theorists also modify existing models to take into account new observations. In some cases, a large amount of observational data that is inconsistent with a model may lead to abandoning it largely or completely, as for [[geocentric theory]], the existence of [[luminiferous aether]], and the [[steady-state model]] of cosmic evolution.{{cn|date=March 2025}}

Phenomena modeled by theoretical astronomers include:
* [[stellar dynamics]] and [[Stellar evolution|evolution]]
* [[galaxy formation and evolution|galaxy formation]]
* [[large-scale structure of the universe|large-scale distribution]] of matter in the [[Universe]]
* the origin of [[cosmic ray]]s
* [[general relativity]] and [[physical cosmology]], including [[string cosmology]] and [[astroparticle physics]].

Modern theoretical astronomy reflects dramatic advances in observation since the 1990s, including studies of the [[cosmic microwave background]], distant [[supernovae]] and [[redshift survey|galaxy redshifts]], which have led to the development of a [[Lambda-CDM model|standard model of cosmology]]. This model requires the universe to contain large amounts of [[dark matter]] and [[dark energy]] whose nature is currently not well understood, but the model gives detailed predictions that are in excellent agreement with many diverse observations.<ref name="PDG">{{cite journal | url=http://pdg.ge.infn.it/2011/reviews/rpp2011-rev-cosmological-parameters.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://pdg.ge.infn.it/2011/reviews/rpp2011-rev-cosmological-parameters.pdf |archive-date=2022-10-09 |url-status=live | title=2013 Review of Particle Physics | author=Beringer, J. | author2=et al. (Particle Data Group) | journal=Phys. Rev. D | date=2012 | volume=86 | issue=1 | page=010001|doi=10.1103/PhysRevD.86.010001|bibcode = 2012PhRvD..86a0001B | doi-access=free }}</ref>