Cosmology I and II, fall 2019

FYS2081 Cosmology I (Kosmologia I) 3.9-18.10
PAP326 Cosmology II (Kosmologia II) 28.10-13.12

Latest course page is now on Moodle: Cosmology I (2020)

Due to the Independence Day holiday, there will be no exercise session on Friday, Dec 6th. The homework will be discussed in the following week.
Lecture on Dec 10 cancelled due to illness.

Lecturer: Hannu Kurki-Suonio, C328 (office hour Mo 10:30-11:30)
Assistant (exercises): Kimmo Kiiveri, A314
The lecturer and assistant can be contacted by e-mail at firstname.lastname(at)

Lectures: Physicum A315, Mo 14-16 and Tu 12-14
Exercise sessions: Physicum A315, Fr 12-14
The course is lectured in English.

The first lecture of Cosmology I is on Tuesday, Sep 3rd, and the first exercise session is on Friday, Sep 13th.
The last lecture of Cosmology I is on Tuesday, Oct 15th.
You can register for Cosmology I in WebOodi until September 3rd midnight.
If you miss this deadline, and still want to register, send a message to or go to see the education coordinators (Physicum C228).
Exam for Cosmology I is in Physicum E207 on Wednesday Oct 23rd, 9.00-13.00
Answers to exam questions: 1, 2, 3, 4, 5

The first lecture of Cosmology II is on Monday, Oct 28th, and the first exercise session is on Friday, Nov 8th.
Exam for Cosmology II is in Physicum D112 on Wednesday Dec 18th, 9.00-13.00
Answer to exam question 1; 2 can be found in lecture notes; 3, 4, 5
You can give feedback in WebOodi after the last lecture.

Exams and grades

The grade is based on both the homework (weight 1/4) and the exam (weight 3/4).
Note that the exams begin sharp on the hour, not quarter past.
A help sheet with information on units and key equations and a particle data table will be handed out in the exam. (Students may not bring books or their own notes to the exam.) Note that many equations in the help sheet are for Cosmology II.
You need to bring your own calculator to the exam.
Exam questions may be of similar nature to homework problems or similar to derivations in the lecture notes. There may also be an essay question.
If the exam date is impossible, students can agree with the lecturer (this must be done before the exam) to take it later, at a departmental exam. In this case the exercise points will contribute to the grade as usual. It is possible to retake the exam once, at a departmental exam (aka general exam), without retaking the course. The grade will then be based entirely on the exam, the exercise points no longer count. In both cases the exam has to be taken before the course is lectured again.
The departmental exams where Cosmology I may be taken are on Dec 13th, Jan 17th, June 5th, and Aug 14th.
The departmental exams where Cosmology II may be taken are on Jan 17th, March 13th, June 5th, and Aug 14th.
The June 5th exam is a remotely supervised examination at 12-15 pm (Note! The exam will last only for three hours). Student will receive detailed instructions on exam arrangements before the exam. If you want to participate in it, send the following information to the lecturer latest on Monday, May 25th: Name of the course, Name of the student, Student number, Student’s email address.
The Aug 14th exam is intended to be a normal exam. Register in WebOodi on 31st May 2020 at the latest.

Lecture notes

Introductory slide show (first lecture)

Cosmology I

Read Chapter 1 by yourself before the second lecture and before doing the first homework. We begin from Chapter 2 in the second lecture (Sep 9th). Appendix A is not required material.
Material covered so far:
Sep 3-23: Chapters 1-3
Sep 24: Sections 4.1-3
Sep 30: Sections 4.4-6
Oct 1: Sections 4.7-10
Oct 7: Sections 5.1-5
Oct 8: Sections 6.6-7
Oct 14: Read Sections 5.6-10
Oct 15: Read Sections 6.1-5 and 6.8

Cosmology II

Chapter 7: Inflation
Chapter 8: Structure Formation
Chapter 9: Cosmic Microwave Background
Appendix B: Quantum Fluctuations during Inflation (not required in Cosmology II)
The above Cosmology II lecture notes in single file

Material covered so far:
Oct 28: Sections 7.1-2
Oct 29: Sections 7.3-7.5.1
Nov 4: Sections 7.5.2-7.7
Nov 5: Sections 7.8-8.1.3
Nov 11: Sections 8.1.4-8.2.2
Nov 12: Sections 8.2.3-9
Nov 18: Sections 8.2.10-8.3.5
Nov 19: Sections 8.3.6-8.4.5
Nov 25: Sections 8.5 (skipped the math, just looked at the prose and the results) and 8.6
Nov 26: Sections 8.7-8.8.2. Read Sec. 8.8.3 at home, needed for homework 11.4
Dec 2: Sections 9.1-3
Dec 3: Sections 9.4-7
Dec 9: Sections 9.5-12
Dec 10: Read Section 9.13

Homework problem sets

Problem sets appear here on Tuesdays (at the latest), and they are due on the following Monday before the lecture. Return your homework to the locker labelled Kosmologia I, at the entry to the A-corridor on the second floor. Solutions to the problems will be discussed in the exercise session on the following Friday.
The first problems set will be given out on Sep 3rd, and the first exercise session is on Sep 13th.

Cosmology I

Cosmology II

Course description

This is the basic course on cosmology. It is divided into two parts, Cosmology I and II, of which Cosmology I should be easier.

Unlike most theoretical physics courses, in Cosmology we will not derive a self-contained theory from basic principles, but we will instead apply known theories to the study of the universe.

In Cosmology I the universe is treated in the approximation, where it is assumed homogeneous and isotropic. This approximation can be used for large scales and the early universe. This gives a basic picture of the composition and evolution of the universe. In Cosmology II we study deviations from homogeneity and isotropy.

Cosmology I is intended for the third (last) year of Bachelor studies or the first year of Master studies. The recommended background for Cosmology I includes mathematical methods (differential and integral calculus, e.g. Mapu I and II), classical mechanics, special relativity, quantum mechanics and statistical physics. Quantum mechanics and statistical physics are not necessary, if the student is willing to accept some results taken from these fields, which are presented in Chapter 4 of lecture notes. Chapter 3 presents the results from general relativity that are needed for Cosmology I. Students who prefer not to have many results presented to them without derivation could take general relativity first (but that would likely push Cosmology I to the second year of Master studies).

Cosmology II is intended for Master studies, to be taken after Cosmology I. Cosmology II requires additional mathematical methods (vector calculus, Fourier analysis and spherical harmonic analysis, e.g. Fymm I and Fymm II, assumed background) and borrows some results from cosmological (general relativistic) perturbation theory and quantum field theory (not assumed).


Here is a list of some cosmology textbooks. The oldest are already partially out of date. It is not necessary to buy any of these books; the lecture notes are sufficient.
E.W. Kolb, M.S. Turner: The Early Universe (Addison-Wesley 1990)
T. Padmanabhan: Structure formation in the universe (Cambridge University Press 1993)
P. Coles, F. Lucchin: Cosmology - The Origin and Evolution of Cosmic Structure (Wiley 1995)
L. Bergström and A. Goobar: Cosmology and Particle Astrophysic (Wiley 1999)
J.A. Peacock: Cosmological Physics (Cambridge University Press 1999)
A.R. Liddle and D.H. Lyth: Cosmological Inflation and Large-Scale Structure (Cambridge University Press 2000)
M. Roos: Introduction to Cosmology, 3rd ed. (Wiley 2003)
S. Dodelson: Modern Cosmology (Academic Press 2003)
V. Mukhanov: Physical Foundations of Cosmology (Cambridge University Press 2005)
S. Weinberg: Cosmology (Oxford University Press 2008)
R. Durrer: The Cosmic Microwave Background (Cambridge University Press 2008)
A.R. Liddle and D.H. Lyth: The Primordial Density Perturbation: Cosmology, Inflation and the Origin of Structure (Cambridge University Press 2009)

Other courses related to cosmology

Galaksit ja kosmologia (Galaxies and Cosmology, in Finnish): An astronomy course with some overlap with Cosmology I (mainly with our Chapters 1 and 3), but mostly about galaxies and their evolution. Lectured in fall 2019.
Galaxy Formation and Evolution: Lectured in fall 2018.
General Relativity: Not needed for Cosmology I and II 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. Last lectured in fall 2015. Will be lectured in spring 2020.
CMB Physics: An advanced course where the physics of the Cosmic Microwave Background and its anisotropy is discussed in detail. Last lectured fall 2007. Was motivated by the Finnish participation in the Planck satellite project. Currently not in the teaching program.
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.
Galaxy Survey Cosmology: A new advanced course in cosmology motivated by the Finnish participation in the Euclid satellite project. Concentrates on the distribution of galaxies (their correlation function and its power spectrum) and weak gravitational lensing. Prerequisites: Cosmology I and II and mathematical methods (FYMM I and II). Was lectured the first time in spring 2017. Lectured again in spring 2019.

Last updated: May 15, 2020