title: Impact of Gravitational Waves from First-Order Phase Transitions on Structure Formation
creator: Döring, Christian
subject: 530
subject: 530 Physics
description: In this thesis we investigate the possibility that gravitational waves emitted from a  first-order phase transition exhibit enough power to alter or generate fluctuations in the  primordial plasma of the early universe and in turn imprint new features into the matter  power spectrum. We approach this task by performing a second order perturbative  expansion of two coupled non-linear equations that monitor the evolution of energy  density gradients in the 1+3 covariant formulation of cosmology. As a result, we find that  adiabatic density fluctuations at second order can be generated from inhomogeneities  in the gravitational wave energy density on sub-horizon scales. We interpret these  fluctuations as baryon acoustic oscillations seeded by gravity radiation and derive their  transferfunction to study their impact on the matter power spectrum. Strength and  scale of the imprinted signatures depend on three phase transition parameters, namely  the latent heat, the duration and the time at which gravitational waves are released.  The amplitude of the signatures is limited by the cosmic variance bound on the matter  power spectrum. We use this constraint to deduce limits for these three parameters and  translate them into a new exclusion region for the relic stochastic gravitational wave  background today. Finally, we discuss our results in the context of first-order phase  transitions occurring in particle models.
date: 2021
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/30841/1/Thesis.pdf
identifier: DOI:10.11588/heidok.00030841
identifier: urn:nbn:de:bsz:16-heidok-308414
identifier:   Döring, Christian  (2021) Impact of Gravitational Waves from First-Order Phase Transitions on Structure Formation.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/30841/
rights: info:eu-repo/semantics/openAccess
rights: Please see front page of the work (Sorry, Dublin Core plugin does not recognise license id)
language: eng