title: An Analysis of Inflationary Correlation Functions creator: Gerstenlauer, Mischa subject: 530 subject: 530 Physics description: Cosmological inflation, which postulates a period of accelerated expansion in the very early universe, has become a major ingredient to modern cosmology over the past decades. In this thesis, we present an analysis of quantum fluctuations which occur during this process and which form the seeds for the growth of structure in our universe. We start by discussing the long-standing question how correlation functions of these fluctuations are affected by infrared divergences. We clarify the origin of these infrared effects and define infrared-safe correlation functions which are not plagued by this issue. Conventional correlation functions are easily recovered from our infrared-safe definition and the corresponding infrared corrections automatically emerge in a resummed, all-orders form. We then continue to discuss deviations of inflationary fluctuations from Gaussian statistics. In particular, we calculate the scale-dependence of this non-Gaussianity for (quasi) local models of non-Gaussian fluctuations and characterize this scale-dependence in terms of new observable parameters. Furthermore, we analyse the possibility of detecting non-Gaussianity by weak lensing measurements. date: 2011 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/12951/1/Mischa_Gerstenlauer_PhD_Thesis.pdf identifier: DOI:10.11588/heidok.00012951 identifier: urn:nbn:de:bsz:16-opus-129512 identifier: Gerstenlauer, Mischa (2011) An Analysis of Inflationary Correlation Functions. [Dissertation] relation: https://archiv.ub.uni-heidelberg.de/volltextserver/12951/ rights: info:eu-repo/semantics/openAccess rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html language: eng