Astrophysics and Cosmology

Part 1 – Introduction to Physical Cosmology ___________________________________________________________________________ -Historical Overview -Cosmological principle -Equivalence Principle -Curvature and its implications -Metric -The Friedmann-Robertson-Walker metric -Dynamics in General Relativity -Friedmann’s equations -Density parameters and cosmological constant -Peculiar solutions to Friedmann’s equations -Benchmark model -Age of the universe -Distances in an expanding universe Part 2 – Proofs of the Big Bang: Geometry and Expansion ___________________________________________________________________________ -Distance measurements: definitions -Standard candles and standard rulers -The distance ladder -Cosmological standard candles -Type Ia supernovae: observational issues -Type Ia supernovae standardization -Observational results -Recent Dark Energy SN results -The measurement of H0 Part 3 – Proofs of the Big Bang: Cosmic Microwave Background ___________________________________________________________________________ Part 3a – The CMB spectrum -Discovery and meaning of the CMB -A modern take on the nature of the CMB -Origin of the CMB blackbody -Recombination, photon decoupling, last scattering -CMB: the confirmation years -The (not so) final word by COBE -COBE mission and results overview -Brief summary of spectral distortions Part 3b – CMB an isotropies -CMB anisotropies: basic quantities -CMB power spectrum: structure and features -Temperature anisotropy measurements -From maps to power spectra (to cosmology) -CMB temperature anisotropy results -CMB polarization anisotropies -CMB polarization: current status and near future Part 4 – Proofs of the Big Bang: the abundances of light nuclei ___________________________________________________________________________ -Big Bang Nucleosynthesis -Deuterium synthesis -The way to Helium -End of BBN -Observational predictions -Observational issues -Current observational constraints Part 5 – Large scale structure ___________________________________________________________________________ -Tools for large scale structure investigations -The matter power spectrum and the 2-point correlation function -Baryon Acoustic Oscillations -Cosmological results from BAO -Weak gravitational Lensing -Cosmology with WL surveys Part 6 – Galaxy clusters ___________________________________________________________________________ -Galaxy Clusters: definitions -Observable properties -Intracluster gas -Cosmology with Galaxy Clusters Part 7 – The Intergalactic Medium and Cosmic Reionization ___________________________________________________________________________ -The Intergalactic medium -Reionization -Observational probes of reionization -HI mapping through the 21cm line Appendix – Bayesian methods in cosmology ___________________________________________________________________________ -The Bayes’ theorem -Advantages of the Bayesian approach -Bayesian inference -Model selection

Required: familiarity with astrophysical processes, astrnonomy and statistics. Suggested: knowledge of the formal foundations of physical cosmology

S. Serjeant, “Observational Cosmology”, Cambridge University Press, 2010 B. Ryden, "Introduction to Cosmology", Cambridge University Press, 2017

The class is taught in about 60 hours of lectures. Lectures offer the foundations to understand the principles and the ideas that will successively be expanded through study of the textbooks and the related suggested references.

Attendance is not mandatory, but strongly advised to support the student in selecting the relevant information available in the overabundant literature available to illustrate the different topics of the syllabus.

The final exam is an oral test. During the test, the candidate is required to present through visualization aids of his/her choice (paper, blackboard, slides) a topic of his/her choice which is of interest for modern observational cosmology. This presentation will consist of a short review illustrating the science case, the methods, the results achieved so far and the future perspectives, if any. After this part, the candidate will undergo a colloquium aimed at assessing his/her formal understanding of topics in the syllabus which were not already discussed in the first part of the exam. The candidate will be evaluated on the basis of the formal correctness of his/her statements, the communication effectiveness, the clarity of presentation, the ability to sustain an articulated discussion of the selected topics, and the consistency of the bibliographic references cited during his/her presentation. The two parts of the exam are evaluated separately and independently, and evenly contribute to the determination of the final grades. Exam duration is no less than 60 minutes.

The class is taught in about 60 hours of lectures. Lectures offer the foundations to understand the principles and the ideas that will successively be expanded through study of the textbooks and the related suggested references.