Search for dissertations about: "non-gaussianity"

Found 5 swedish dissertations containing the word non-gaussianity.

  2. 1. Probing the early Universe with B-mode polarization : The Spider instrument, optical modelling and non-Gaussianity

    Author : Adriaan Judocus Duivenvoorden; Katherine Freese; Jón Emil Gudmundsson; Juan García-Bellido; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; cosmic microwave background; early universe; polarimetry; telescopes; fysik; Physics;

    Abstract : 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. READ MORE

  4. 2. Effects of the Higgs field on Inflation and Reheating

    Author : Aliki Litsa; Katherine Freese; Jens Jasche; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; inflation; reheating; Higgs; non-gaussianity; cosmological perturbations; Theoretical Physics; teoretisk fysik;

    Abstract : 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. READ MORE

  5. 3. Tomographic studies of the 21-cm signal during reionization : Going beyond the power spectrum

    Author : Sambit K. Giri; Garrelt Mellema; Benoît Semelin; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; reionization; non-gaussianity; first stars; image processing; Astronomy; astronomi;

    Abstract : 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). READ MORE

  6. 4. Reconstructing the Primordial Seeds of Cosmic Structures in Galaxy Surveys

    Author : Adam Johansson Andrews; Jens Jasche; David Marsh; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

    Abstract : 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. READ MORE

  7. 5. Random Models in Time and Space with Financial, Economics and Engineering Applications : Structural Covariance in Space and Stochastic Variability in Time

    Author : Nima Shariati; Statistiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Cross-border spillover; Inter- and intralocation effects; Multivariate spatial regression models; Panel data; Spatial econometric models; Gamma distributed variances; Generalized Laplace distribution; Modulated volatility; Non-Gaussian time series; Road profile; Spatial vector autoregressive model; Outlier; Robust control chart; Robust estimation;

    Abstract : 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. READ MORE