Galaxy Survey Cosmology

Hannu Kurki-Suonio

PAP341 Galaxy Survey Cosmology, 10 credits

PAP352 Galaxy Survey Cosmology, 5 credits

PAP353 Gravitational Lensing, 5 credits

This is the public homepage for my galaxy survey cosmology course at the University of Helsinki.
I lectured the course in 2017, 2019, 2021, and 2023. In 2023 the course was lectured as two 5-credit courses, PAP352 Galaxy Survey Cosmology by me and PAP353 Gravitational Lensing by Elina Keihänen.
For the 2023 Moodle pages, go to Galaxy Survey Cosmology (2023) and Gravitational Lensing (2023)
The 2023 version of the lecture notes (part 1) is available below.

Lectures (Hannu Kurki-Suonio)
Exercises (Elina Keihänen, Kimmo Kiiveri)

This is a new special course in cosmology, lectured the first time in spring 2017. While in the decades 2000-2020 the most important new cosmology data came from observations of the cosmic microwave background (CMB), especially by the WMAP (NASA) and Planck (ESA) satellites; the 2020s will be the decade of large galaxy surveys. These surveys include the ongoing ground-based surveys like KiDS (Kilo-Degree Survey) and DES (Dark Energy Survey), and the future LSST (Large Synoptic Survey Telescope); and the space-based surveys by the Euclid (ESA) and WFIRST (NASA) satellites.

The two main cosmological probes of these galaxy surveys are the distribution of galaxies and the distribution of all matter as measured by the gravitational lensing effect. The main statistical mathematical tools are correlation functions, both of galaxy positions and shear, i.e., the distortion of galaxy images due to (weak) lensing. These quantities can be used to constrain cosmological models. The main goal is to improve our understanding of what is commonly called Dark Energy, the cause of the acceleration of the expansion of universe; but a wealth of other astronomical and cosmological information is also obtained.

The course covers the methods used in galaxy survey cosmology and what we already know about the Universe from them. The first part of the course is about the galaxy distribution and the second part about gravitational lensing. The lecturer and assistant are members of the Euclid Collaboration.
There will be no exam; the grade is based on homework.
The course is lectured in English, unless everyone speaks Finnish.

The first part of the course is partly based on Peacock, Chapter 16, and MBW, Chapter 6. The foundation of the field was laid by Peebles' 1980 textbook. The second part of the course, on gravitational lensing and especially on weak lensing surveys, will follows Parts I and III of the Schneider et al 2006 book.

The course is relatively mathematical in nature; we use Fourier and spherical harmonic analysis, and special functions. Recommended background includes Cosmology I and II and Mathematical Methods of Physics (FYMM I and FYMM II).

MBW Sec. 2.7 gives a 4-page introduction to the field. I recommend reading it before the first lecture.

Lecture notes

Introductory presentation
Galaxy Survey Cosmology, part 1, 31.5.2023 version
Handwritten lecture notes for part 2:
Lecture 1 (March 11th)
Lecture 2 (March 14th)
Lecture 3 (March 18th)
Lecture 4 (March 21st)
Lecture 5 (March 25th: read at home)
Lecture 6 (April 1st)
Lecture 7 (April 4th)
Lecture 8 (April 4th)
Lecture 9 (April 8th)
Lecture 10 (April 11th)
Lecture 11 (April 15th)
Lecture 12 (April 15th and 25th)
Lecture 13 (April 29th)
Additional notes to Galaxy Survey Cosmology, part 2

Homework problem sets

The problem sets are given out on Mondays. You should return your solutions to Elina, e.g., to her mailbox in the third floor C corridor, before the lecture of the following Monday.

Literature

P.J.E. Peebles: The Large-Scale Structure of the Universe (Princeton University Press 1980)
J.A. Peacock: Cosmological Physics (Cambridge University Press 1999) - Errata
S. Dodelson: Modern Cosmology (Academic Press 2003)
H. Mo, F. van den Bosch, and S. White (MBW): Galaxy Formation and Evolution (Cambridge University Press 2010) - there are several copies in the Library, also available as eBook through Helka
P. Schneider, J. Ehlers, E.E. Falco: Gravitational Lenses (Springer 1992)
P. Schneider, C. Kochanek, J. Wambsganss: Gravitational Lensing: Strong, Weak and Micro (Springer 2006)
M. Kilbinger: Cosmology with cosmic shear observations: a review, arXiv:1411.0115, Rep. Prog. Phys. 78, 086901 (2015)

Galaxy surveys

SDSS
KiDS
DES
LSST
Euclid
WFIRST

Other courses related to cosmology

Cosmology I and II : The basic courses in cosmology. Lectured every fall.
Galaksit ja kosmologia (Galaxies and Cosmology, in Finnish): An astronomy course with some overlap with Cosmology I (mainly with Chapters 1 and 3), but mostly about galaxies and their evolution. Lectured in fall 2017.
Galaxy Formation and Evolution: Lectured in fall 2018.
General Relativity: Not needed for Galaxy Survey Cosmology, but essential if you want to study cosmology further. Lectured every spring term.
Cosmological Perturbation Theory: An advanced course in cosmology, covering Cosmology II material (except CMB) at a much deeper level. Prerequisites: Cosmology I and II, General Relativity I.
Cosmological Parameter and Model Estimation: A hands-on course on using observational data to determine cosmological parameters and compare cosmological models. Was lectured in spring 2013. Currently not in the teaching program, but may come back in a few years.
Last updated: June 2, 2023