Unit:
Κατεύθυνση ΑστροφυσικήLibrary of the School of Science
Supervisors info:
Τετράδης Νικόλαος, Καθηγητής, Τμήμα Φυσικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Original Title:
Κοσμολογικός Πληθωρισμός, Φάσμα των Διακυμάνσεων και Αρχέγονες Μελανές Οπές
Translated title:
Cosmological Inflation, Spectrum of the Perturbations and Primordial Black Holes
Summary:
Highly overdense regions of inhomogeneities in the primordial Universe can undergo direct
gravitational collapse to form black holes. We discuss the production of primordial black
holes in the context of single-field inflation and the possibility that they constitute the
dark matter today. We analyze numerically a single-field string inflationary model, which
leads to the production of primordial black holes of mass M ≈ 10 ^(-15) solar masses and an abundance at the level of 10% of the dark matter today. The potential of the model has a near-inflection point, where the power spectrum is enhanced due to a period of ultra-slow-roll inflation. This feature triggers efficient black hole production within a certain range of masses. The background field is analysed by solving the Friedmann and Klein-Gordon equations. We also solve the Mukhanov-Sasaki equation for the curvature perturbations, which leads to the determination of the primordial power spectrum and the residual black-hole abundance.
Main subject category:
Science
Keywords:
Cosmological Inflation, Primordial Black Holes, Perturbations, Power Spectrum
