La Rosa, Martina
(2025)
Ultralight vector dark matter from non-slow-roll inflation.
[Laurea magistrale], Università di Bologna, Corso di Studio in
Physics [LM-DM270]
Documenti full-text disponibili:
![[thumbnail of Thesis]](https://amslaurea.unibo.it/style/images/fileicons/application_pdf.png) |
Documento PDF (Thesis)
Disponibile con Licenza: Salvo eventuali più ampie autorizzazioni dell'autore, la tesi può essere liberamente consultata e può essere effettuato il salvataggio e la stampa di una copia per fini strettamente personali di studio, di ricerca e di insegnamento, con espresso divieto di qualunque utilizzo direttamente o indirettamente commerciale. Ogni altro diritto sul materiale è riservato
Download (3MB)
|
Abstract
Inflation not only provides a promising explanation for the observed structure of our universe;
but also reveals a novel and elegant mechanism for the production of dark matter, distinct from
the historically considered scenarios. Among the others, inflation naturally generates vector field
fluctuations which, after being stretched to super-horizon scales and re-entering the horizon, are
viable dark matter candidates. The longitudinal mode of a massive vector boson is especially
noteworthy, being abundantly produced during inflation. Unlike scalars and tensors which are
typically produced with a nearly scale-invariant spectrum, the longitudinal mode inherits unique
dynamics from its inflationary origin, satisfying cosmological constraints and providing a robust
dark matter candidate.
In this thesis, we propose a mechanism through which ultralight dark matter is generated
during inflation. We introduce a brief departure from slow-roll inflation to address the challenge
of producing a realistic dark matter candidate and explore its consequences. The violation of
slow-roll conditions during inflation induces a rapid change in the vector boson mass, producing
significant features in the power spectrum. We show that this rapid variation, occurring during
a short non-slow-roll phase, enhances the power spectrum and naturally generates an ultralight
dark matter relic with extremely small vector masses, allowing for the inclusion of candidates with
masses as low as m ≃ 10^(−19) eV or even smaller.
Our results demonstrate that the non-standard evolution of inflationary parameters strongly
amplifies the longitudinal mode fluctuations, enabling ultralight bosons to be naturally produced
by quantum fluctuations during inflation. This mechanism establishes a theoretically consistent
pathway for generating ultralight dark matter and provides a framework to explore a unified
inflationary origin for mixed dark matter scenarios.
Abstract
Inflation not only provides a promising explanation for the observed structure of our universe;
but also reveals a novel and elegant mechanism for the production of dark matter, distinct from
the historically considered scenarios. Among the others, inflation naturally generates vector field
fluctuations which, after being stretched to super-horizon scales and re-entering the horizon, are
viable dark matter candidates. The longitudinal mode of a massive vector boson is especially
noteworthy, being abundantly produced during inflation. Unlike scalars and tensors which are
typically produced with a nearly scale-invariant spectrum, the longitudinal mode inherits unique
dynamics from its inflationary origin, satisfying cosmological constraints and providing a robust
dark matter candidate.
In this thesis, we propose a mechanism through which ultralight dark matter is generated
during inflation. We introduce a brief departure from slow-roll inflation to address the challenge
of producing a realistic dark matter candidate and explore its consequences. The violation of
slow-roll conditions during inflation induces a rapid change in the vector boson mass, producing
significant features in the power spectrum. We show that this rapid variation, occurring during
a short non-slow-roll phase, enhances the power spectrum and naturally generates an ultralight
dark matter relic with extremely small vector masses, allowing for the inclusion of candidates with
masses as low as m ≃ 10^(−19) eV or even smaller.
Our results demonstrate that the non-standard evolution of inflationary parameters strongly
amplifies the longitudinal mode fluctuations, enabling ultralight bosons to be naturally produced
by quantum fluctuations during inflation. This mechanism establishes a theoretically consistent
pathway for generating ultralight dark matter and provides a framework to explore a unified
inflationary origin for mixed dark matter scenarios.
Tipologia del documento
Tesi di laurea
(Laurea magistrale)
Autore della tesi
La Rosa, Martina
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Indirizzo
THEORETICAL PHYSICS
Ordinamento Cds
DM270
Parole chiave
Ultralight Dark Matter,Vector Dark Matter,Inflation,Cosmological perturbations,Non-standard Inflation
Data di discussione della Tesi
26 Settembre 2025
URI
Altri metadati
Tipologia del documento
Tesi di laurea
(NON SPECIFICATO)
Autore della tesi
La Rosa, Martina
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Indirizzo
THEORETICAL PHYSICS
Ordinamento Cds
DM270
Parole chiave
Ultralight Dark Matter,Vector Dark Matter,Inflation,Cosmological perturbations,Non-standard Inflation
Data di discussione della Tesi
26 Settembre 2025
URI
Statistica sui download
Gestione del documento: