Sökning: "non-gaussianity"
Hittade 5 avhandlingar innehållade ordet non-gaussianity.
1. Probing the early Universe with B-mode polarization : The Spider instrument, optical modelling and non-Gaussianity
Sammanfattning : One of the main goals of modern observational cosmology is to constrain or detect a stochastic background of primordial gravitational waves. The existence of such a background is a generic prediction of the inflationary paradigm: the leading explanation for the universe's initial perturbations. LÄS MER
2. Effects of the Higgs field on Inflation and Reheating
Sammanfattning : The model of inflation - a period of accelerated expansion in the very early Universe - was introduced to give solutions to a number of problems encountered in the Standard Big Bang paradigm. Additionally, due to its quantum nature, inflation is able to generate the necessary primordial inhomogeneity “seeds”, which eventually evolve into large-scale structures. LÄS MER
3. Tomographic studies of the 21-cm signal during reionization : Going beyond the power spectrum
Sammanfattning : The formation of the first luminous sources in the Universe, such as the first generation of stars and accreting black holes, led to the ionization of hydrogen gas present in the intergalactic medium (IGM). This period in which the Universe transitioned from a cold and neutral state to a predominantly hot and ionized state is known as the Epoch of Reionization (EoR). LÄS MER
4. Reconstructing the Primordial Seeds of Cosmic Structures in Galaxy Surveys
Sammanfattning : One of the most outstanding questions in modern cosmology concerns the physical processes governing the primordial universe and the origin of cosmic structure. These primordial signals appear in a variety of cosmic large-scale structure probes, e.g. LÄS MER
5. Random Models in Time and Space with Financial, Economics and Engineering Applications : Structural Covariance in Space and Stochastic Variability in Time
Sammanfattning : In this thesis, we model stochastic processes in time and space. We focus on the processes whose covariance structure is either changing over the time span, or depends on the location in space. We develop models that appropriately describe and analyze such data behaviors in various different fields including finance, economics and engineering. LÄS MER