Alberto Franceschini

Picture of Alberto Franceschini

Courses

0. The Homogeneous and Isotropic Universe (Summary)
Hubble law. The Cosmological Principle. Isotropic curved spaces. The Robertson-Walker metric. Cosmological dynamics and models. Observables. Redshift. Distances. Time-redshift relations. Hubble diagrams. The cosmological constant.

1. The Large Scale Structure of the Universe. Local properties. General and structural properties of the universe. Angular and spatial correlation functions. Higher order correlations. Limber relation. Power-spectrum. Observational data on the large scale structure. The initial power-spectrum. 3D mapping of galaxies, clusters, AGNs. Counts-in-cells. Fractals and topology.

2. Gravitational lensing
Point-like lenses and isothermal spherical distributions. Lens potentials. Einstein radius. Lensing cross-sections. Lensing effects on time lags. Observations. Estimate of the total galaxy cluster mass. Estimates of H0. Effects of a cosmological constant in the lensing statistics. Micro-lensing and weak-lensing. Mapping of the mass distribution.

3. Cosmological evolution of perturbations in the cosmic fluid.
Cosmological evolution of perturbations in the cosmic fluid. General equations in a static universe and in an expanding one. Evolution in a matter dominated universe. Hubble drag.

4. Peculiar motions of galaxies and structures.
Deviations from the Hubble flow, peculiar velocity fields in the cosmo. Observations of peculiar velocity fields. The cosmic viral theorem. Origin of the large scale motions. Constraints on the cosmological parameters.

5. Brief thermal history of the Universe
The matter and radiation content of the Universe. Energy densities and their evolution. Radiation-dominated universes. The epoch of recombination and equivalence. Time-scales of cosmic evolution. Primordial nucleo-synthesis.

6. The Cosmic Microwave Background
Discovery of the CMB. Observations from ground and from space. COBE, WMAP & Planck. Origin of the CMB.
Spatial properties, isotropy of the CMB. Statistical description of the angular structure.
Origin of the CMB angular fluctuations. Physical processes in operation on the large scales. Fluctuations on intermediate angular scales. Contributions of sources. Cosmological re-ionization. Constraints on the cosmological parameters. The CMB spectrum. Spectral distorsions. Sunyaev-Zeldovich effect. Observational limits on the spectral distorsions and their implications. Polarization properties.

7. The Primordial Universe, Big Bang, phase transitions, cosmological inflation
Cosmological horizons. Big Bang singularity. Planck time. Standard model of elementary particles. Fundamental interactions. Cosmological phase transitions. Open questions about the standard Big Bang model. The horizon problem. The flatness problem. Cosmological inflation and solutions to the problems. The Anthropic Principle.

8. Origin and Evolution of the Cosmological Structure
Generation of the perturbation field (the Primordial Power Spectrum). Fluctuations from inflation. The cosmic fluid: the Dark Matter component. Properties of the Cold and Hot Dark Matter. Scales and masses involved within the Cosmological Horizon. Scale-invariant primordial spectrum and the horizon entrance of perturbations of different scales. Free-streaming and damping. Stagnation. Evolution of the DM field. Transfer function. LambdaCDM cosmology. Evolution of the cosmic fluid after recombination. Collapse of DM halos and Press-Schechter theory. Galaxy formation.

9. The Post-Recombination and High-Redshift Universe
Intergalactic diffuse gas. Absorption-lines in quasar spectra. The missing baryon problem. Evolutionary history of star formation, the stellar mass function, heavy element production, background radiations. Evolution of Active Galactic Nuclei.

Category: A.A. 2019 - 2020 / Corsi di laurea magistrale / SC2490 - ASTROPHYSICS AND COSMOLOGY