Cosmology

Lecturer:
Prof. Dr. Matteo Maturi (ITA/ZAH, ITP)
Head tutor: Serena Giardino (serena.giardino@aei.mpg.de)

Space and time:

• Winter semester, 2023/24
• From October 16th to February 1st
• Tuesday 09:15-11:00 (INF227/HS 2)
• Thursday 09:15-11:00 (INF227/HS 2)

Overview:
The lectures will be about modern cosmology. During the lectures you will learn about: the basics of General Relativity; how we model a homogeneous and isotropic universe; dark matter, dark energy and their role; cosmic inflation; the thermal processes that took place during the history of our universe; cosmic structure formation both in the linear and in the non linear regime; after having introduced the theory I will discuss the main observations that provide us the current picture of our universe.

Prerequisites:
PTP2 and General Relativity are helpful but not mandatory.

Format:
The lectures will be held in person and will be recorded. Lecture notes about what will be present at the blackboard and additional material will be provided. The notes will be complementary to other material/books and present full derivations. I will start slow to build a solid background. The lectures and exercise classes are held in English and will be recorded.

Enrollment:
To get credit points for the lectures it is necessary to enroll through this website.
If you are still missing the credentials (immatriculation, ID number, ...) and can not log-in, ask the head tutor to be enrolled manually.

Material and exercises:
You find everything in this page.

Exam:
Written. February 6th, 9am, gHS Philosophenweg 12

Exam review:
Two or three days after the exam. Date TBD

Admission to the exam:
Attend at least 50% of the tutorials AND gain 3 points by: Presenting an exercise (1 point) or actively participating in the discussion during the tutorials (max 1 point per tutorial). If participation is below 30%, it is required to hand in 3 full exercise sheets that will be graded.

Lehre, Studium und Forschung:
Lecture Token MKTP5 (8CP): LSF
 

Index of the lectures

Introduction
    - What is cosmology about?
    - History of cosmology at large
    - Special relativity
    - General relativity

Homogeneous and isotropic universe
    - Einstein equations
    - Friedman-Lamaitre-Robertson-Walker (FLRW) metric
    - Friedmann equations   =>  H(a), ρ(a), T(a)
    - The cosmological parameters
    - The ingredients: radiations, dark matter, baryons, dark energy/lambda
    - Distances in cosmology
    - The distance ladder

Dark energy
    - The cosmological constant lambda
    - Problems of lambda
    - Dark energy model
    - Equation of state of dark energy
    - Modifying gravity, example: Horndeski theory

Dark matter
    - Properties
    - Particle candidates
    - Indirect detections
    - Direct detections
    - Problems

Cosmic inflation
    - Solving problems of the Hot Big-Bang model
    - The inflaton field
    - Origin of the initial energy density fluctuations
    - Constraints on inflation

Thermal History
    - Summary of equilibrium thermodynamics
    - Cosmological nucleosynthesis
    - Neutrino decoupling (CνB)
    - Matter-radiation decoupling (CMB)

Linear structure formation
    - Origin of the fluctuations
    - Hydrodynamics (Continuity, Euler, Poisson)
    - Linearization, perturbative approach
    - Set comoving coordinates
    - The growth factor D+(a)
    - Relativistic structure formation
    
Statistics of the perturbations
    - The power spectrum and the correlation function
    - Normalization of the power spectrum and σ8
    - CDM power spectrum
    - The bias factor
    - Peculiar velocities
    - BAOs
    - Non linear correlations

Non linear structures
    - The Zel’dovich approximation
    - Spherical collapse
    - Press-Schechter mass function
    - N-Body numerical simulations
    - Other mass functions
    - Dark matter haloes: profiles, virial theorem
    - Galaxies: types, velocity profiles
    - Clusters of galaxies: X-rays, SZ, Optical, baryonic fraction, mass estimates

Observations and cosmological probes
    - CMB
    - Type-Ia supernovae
    - Galaxy clustering
    - Redshift-space distortion
    - Gravitational lensing
    - Galaxy clusters

Videos of the lectures
    - Link

Suggested readings:
    - the scripts you find below in the "Material" section
    - the following books you find in the university library:
      Cosmological Physics (John A. Peacock)
      Modern Cosmology (S. Dodelson, F. Schmidt)