Astronomy 8873: Cosmology and Structure Formation
Spring 2026

Handouts

• Course Syllabus

Lecture notes

All notes are in pdf.

• I. Observational Basis of the Standard Model
  Slides in pptx or pdf.
• II. General Relativity
  
• III. Homogeneous Cosmological Models: Geometry
  
• IV. Homogeneous Cosmological Models: Dynamics
  
• V. The Cosmic Microwave Background
  (updated 2/17).
• VI. Big Bang Nucleosynthesis
  Slide in pptx or pdf.
• VII. The Early Universe
  , updated 3/22/26, Turner/Gonzales History of the Universe
• VIII. Large Scale Structure: Observables and Linear Evolution
  , updated 4/9/26.
• IX. The LCDM Model, updated 4/9/26. Slides in pptx or pdf.
• X. CMB Anisotropies. Slides in pptx or pdf.
• XI. Inflation.
• XII. Non-linear clustering, halos, and galaxies. Slides in pptx.

Problem sets and short questions

• Short questions 1, gravitational redshift.
• Problem set 1, due 1/30, simple model of the DM halo.
• Short questions 2 (in class, 2/11), cosmic expansiom history.
• Problem set 2, due 2/13, cosmological parameters and their evolution.
• Short questions 3, mean free path before recombination.
• Problem set 3, due 3/2, big bang nucleosynthesis.
• Short questions 4, natural units.
• Problem set 4, due 3/23, WIMP dark matter freezeout.
• Problem set 5, due 4/10, spherical collapse.
• Problem set 6, due 4/20, DESI and cosmological parameters.
  • desi.tbl1 data table for PS 6.
  • desi.tbl1.ratio data table for PS 6.
  • cosmodist2.py code for PS 6.
  • desi_chisq.py code for PS 6.
  • desy5sn.tbl DES supernova data table for PS 6.

External links

• A new way to visualize General Relativity. This video proposes an alternative to the conventional "rubber sheet" visualization of curved spacetime, one that better represents what is going on in GR.
• Supernova cosmology paper from the Dark Energy Survey (DES) Collaboration. A follow-up paper using a revised calibration is here.
• Some papers on the Gunn-Peterson effect and Lyman-alpha forest (I can suggest many more if you are interested: Gunn and Peterson 1965, Hernquist et al. 1996, Peeples et al. 2010
• Two papers with good illustrations and conceptual descriptions of cosmological N-body simulations and their application to making mock survey data sets:
  Cole et al. 1997
  Cole et al. 1998
• Animations of the impact of cosmological paramters on CMB anistropy, from Max Tegmark's web site.
• Flight through the Sloan Digital Sky Survey map of the universe.
• Flight through structure in the nearby universe.
• Flight outward through the Hubble Ultra Deep Field. As we go out to greater distances, we are effectively looking backward in time. The most distant galaxies here are about 12 billion light years away.
• Computer simulation of the gravitational clustering of dark matter. The expansion of the universe has been scaled out, so that we are always looking at the same matter. Rotation helps to see the 3-dimensional structure.
• Computer simulation of gravitational clustering of dark matter. This video shows a 2-dimensional projection of a 3-dimensional simulation, much larger in volume than the previous two. The expansion of the universe has again been scaled out.
• Flight through the large scale distribution of dark matter in a computer simulation.
• Another computer simulation of dark matter clustering. This time the expansion of the universe hasn't been scaled out, but the video zooms in to show the formation of a single dark matter halo.
• Computer simulation of the formation of a disk galaxy. In addition to gravity, there are pressure forces on the gas, and it is the combination of gravity, rotation, these pressure forces, and dissipation of energy that leads to the formation of a thin disk.
• An even better computer simulation of the formation of a disk galaxy. The small panels show a larger scale view (at lower left) and zoomed in views of the gas and stars (at lower right).