992DF - FISICA DELLE PARTICELLE E COSMOLOGIA 2024
Schema della sezione
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Resources
introduction to cosmology:
- lecture notes by Baumann http://cosmology.amsterdam/education/cosmology/
- book by Baumann (Baumann, D. (2022) Cosmology. Cambridge: Cambridge University Press.)
- book by Kolb & Turner (The Early Universe, Front. Phys. 69 (1990), 1-547 doi:10.1201/9780429492860)cosmological constant:
- introductory review by Carroll https://arxiv.org/abs/astro-ph/0004075
- Casimir effect is treated in the QFT notes by Tong https://www.damtp.cam.ac.uk/user/tong/qft.html
- anthropic argument: see Carrolldark matter
- the most comprehensive review is this book: https://www.cambridge.org/core/books/particle-dark-matter/B03C934EAB188884EFC6B02432632496. Many (most?) chapters can be found on arXiv as preprints
- historical perspective https://arxiv.org/abs/1605.04909
- some nice set of lectures: https://arxiv.org/abs/1603.03797 by Mariangela Lisanti, https://arxiv.org/abs/1301.0952 by Stefano Profumo
- relic abundance: Gondolo&Gelmini (https://inspirehep.net/literature/304505)axions and axion DM
- lectures by Anson Hook (https://arxiv.org/abs/1812.02669)
- long/complete review by Marsh (https://arxiv.org/abs/1510.07633)
- Kolb & Turner
classical fields in cosmology
- quantum to classical transition: Anthony Duncan, The Conceptual Framework of Quantum Field Theory, Oxford University Press
- Robert Brandenberger, Quantum Field Theory Methods and Inflationary Universe Models, https://inspirehep.net/literature/14969gravitational waves
- a good introduction is -
Articoli proposti per il seminario di esame (aggiungerò altri riferimenti man mano)
- Freeze-out della materia oscura studiato in dettaglio
Gondolo & Gelmini, Nucl.Phys.B 360 (1991) 145-179 - eccezioni al calcolo del freeze-out visto a lezione
Griest & Seckel, Phys.Rev.D 43 (1991) 3191-3203 - Freeze-in DM prodotta tramite scattering
Teresi & Heeck, https://arxiv.org/abs/1706.09909 - Accoppiamento dell'assione QCD ai mesoni con la Lagrangiana chirale
Grilli di Cortona et al., https://arxiv.org/abs/1511.02867
Hook, https://arxiv.org/abs/1812.02669 - Discutere in dettaglio un tipo di ricerca di assioni
- Axion superradiance
- Bound su particelle leggere dato dal numero effettivo di neutrini \Delta N_{eff}
- Cosmic strings (Hindmarsh and Kibble https://inspirehep.net/literature/380099)
- Buchi neri primordiali (PBH): meccanismo di formazione, cenni ai limiti sulla frazione f_PBH (https://arxiv.org/pdf/1801.05235)
- Tunnelling in QFT
- Evidenze astrofisiche/cosmologiche dell'esistenza della materia oscura
- Freeze-out della materia oscura studiato in dettaglio
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Introduction. What is cosmology. Why are cosmology and high energy physics related. Units. Planck mass. Timeline.
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FRLW metric. Hubble constant. Redshift. Energy density and pressure, energy-momentum tensor. Continuity equation. Equation of state. Friedmann equations and their solution.
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Energy density and pressure, energy-momentum tensor. Continuity equation. Equation of state. Friedmann equations and their solution. EOS for non-relativistic matter, radiation, cosmological constant and kinetic energy. Cosmic history. Critical density.
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Present energy budget of the Universe. Brief summary of the cosmological history. Flatness of the Universe. Age of the Universe. Stellar age problem.
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Cosmological constant in the Einstein equation and as a new type of fluid. Cosmological constant "problem". Potential energy of a scalar field. Fine-tuning and phase transitions. Vacuum energy in QFT.
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Vacuum energy and Casimir effect. Measuring the accelerated expansion with SN Ia. Anthropic principle.
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The Universe at thermal equibrium. Energy density. Effective number of relativistic degrees of freedom.
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Evidences of the existence of DM
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General properties of DM. Distribution at the galactic scale. Lower mass bounds: ultra-light bosons, Tremaine-Gunn bound. Electric charge. Self-interactions. DM lifetime. DM is cold: free-streaming length and matter power-spectrum.
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DM is cold: free-streaming length and matter power-spectrum. Thermal production of DM and freeze-out. Annihilation rate. Departure from thermal equilibrium. Hot freeze-out. Cowsik-McClelland bound on hot DM mass. Neutrino decoupling.
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Cold freeze-out. WIMP miracle. Chemical vs. kinetic decoupling. Boltzmann equation. Liouville and collision operators.
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Boltzmann eq for WIMP pair annihilation. Role of \Gamma/H. Remarks on the cross section. Mass window of cold relics produced via freeze-out. Exceptions: resonances, thresholds, coannihilations, Sommerfeld enhancement, bound states.
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Entropy injection from the decay of a heavy, decoupled species. Effect on DM abundance. Direct DM searches.
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Indirect Detection (with focus on photons). DM from neutrinos in the Sun. DM at colliders.
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Introduction to axions. Strong CP problem. Electric dipole moment of the neutron. QCD axion.
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Axion-like particles. Axions as DM: thermal production, decay of cosmic strings
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Axion misalignment. Solution of the equation of motion. Relic abundance. Initial angle: PQ breaking during or after inflation. Axion searches.
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General introduction to Gravitational Waves. GWs propagate freely from the very early universe. Linearized gravity around Minkowski. Lorentz gauge condition, transverse-traceless gauge. GWs have 2 polarizations. Linear expansion around Minkowski, with matter. Definition of GWs as radiative and gauge-invariant tensor perturbations.
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GWs in a curved background. Scale separation for distinguishing GWs from the background. Energy-momentum tensor and GW energy. GWs in FLRW. Solution of the homogeneous equation in the sub-horizon and super-horizon limits. GWs of cosmological origins form a stochastic background.
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GWs of cosmological origins form a stochastic background. Power spectrum. Energy density. Propagation of GWs through cosmic history. Solution of the inhomogeneous equation and GW spectrum today. Sensitivity range of GW experiments.
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Gravitational waves from phase transitions in the early universe
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Inflation. Motivations. Single field inflation. Slow-roll. Horizon crossing. Perturbative reheating.
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Inflationary perturbations: overview. Massless scalar field in de Sitter. Quantization and choice of the Bunch-Davies vacuum. Number of particles and quantum to classical transition. Power spectrum. Massive field in quasi-de Sitter space.
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Inflaton perturbations. Choice of coordinates and definition of perturbations. Gauge invariant curvature perturbations. Calculation of \zeta and its power spectrum. Sachs-Wolfe effect and temperature perturbations.